STUDENT SUCCESS IN AN INQUIRY-BASED LABORATORY: THE EFFECT OF PRE-CLASS ACTIVITIES AND STUDENT PREPARATION By MELISSA ROSE GENTRY Bachelor of Science in Secondary Science Education Oklahoma State University Stillwater, OK 2002 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE July, 2005 STUDENT SUCCESS IN AN INQUIRY-BASED LABORATORY: THE EFFECT OF PRE-CLASS ACTIVITIES AND STUDENT PREPARATION Thesis Approved: Donald P. French Thesis Adviser Margaret S. Ewing Richard J. Bryant A. Gordon Emslie Dean of the Graduate College ii ACKNOWLEDGEMENTS There are many people who assisted me with the production of this thesis and provided guidance during my graduate studies. First, I would like to thank my committee members. Dr. Donald French, my advisor, gave me the opportunity to work both for him and with him. I can never fully describe the irreplaceable guidance he provided me on this thesis as well as my coursework, teaching philosophy, and attitude toward research. I thank him for always keeping his door open and driving me to excel. Dr. Margaret Ewing was always available for assistance and support. Her perspectives on my thesis and on being an instructor and graduate student were invaluable to me. I thank her for being receptive to this project and willing to assist me in my pursuit to graduate. Dr. Richard Bryant provided constant encouragement. His positive outlook on this project (and life in general) made it such a pleasure to work with him. I also would like to acknowledge him for introducing me to scientific inquiry and being such an influential instructor in my life. I would like to recognize Dr. Carla Goad for her assistance with the statistical analyses of this project. I truly appreciate the time she devoted to coding SAS with me. I would also like to thank Dr. Tim O’Connell and Dr. Joe Bidwell among the many other zoology faculty members that either gave me advice or support. For direction and understanding, I relied a great deal on other graduate students, especially Cathy, Kathleen, Moria, Tarren, Tiffany, Sara, Brooke, and Mike. I would also like to thank Dr. Connie Russell for her encouragement, kindness, and unique perspective. Finally, I would like to express gratitude for my loved ones and their contributions: my mom, for acting as my life and career counselor; my dad, for his unwavering confidence in all that I do; Ken and Rhonda, for loving me as their own; my Bobo, James, for being my source of inspiration; my sisters and their families, for their understanding and patience; and my friends, especially my girls, Meagan, Jennifer, Melissa, and Amy, for their constant support and praise. I would not have accomplished any of this without their love and devotion. iii TABLE OF CONTENTS Chapter Page I. INTRODUCTION ......................................................................................................1 The Problem.............................................................................................................1 Previous Research....................................................................................................4 Course Design..........................................................................................................6 Objectives of the Study............................................................................................8 II. METHODS................................................................................................................9 Subjects ....................................................................................................................9 Analyses of Student Grades .....................................................................................9 Regression Analyses ........................................................................................10 Analyses of Covariance ...................................................................................12 Analyses of the Student Survey .............................................................................13 III. RESULTS ..............................................................................................................15 General Regression Models ...................................................................................16 ANCOVA Including Lab Investigation .................................................................24 ANCOVA Including Section .................................................................................34 ANCOVA Including Teaching Assistant...............................................................44 Analyses of the Student Survey .............................................................................54 Summary of Results...............................................................................................58 IV. DISCUSSION........................................................................................................62 Findings..................................................................................................................62 General Regression Models .............................................................................62 Sources of Variation ............................................................................64 ANCOVA Including Lab Investigation ...........................................................67 ANCOVA Including Section ...........................................................................69 ANCOVA Including Teaching Assistant.........................................................71 Analyses of the Student Survey .......................................................................75 iv Conclusions............................................................................................................76 Recommendations for Future Research .................................................................77 V. LITERATURE CITED ..........................................................................................80 VI. APPENDIXES......................................................................................................85 Appendix A............................................................................................................85 Appendix B ............................................................................................................87 Appendix C ............................................................................................................88 v LIST OF TABLES Title Page I. Regression Analysis of Each Student’s Average Pre-lab and Planning Form Scores…………………………………………………….. 17 II. Regression Analysis of Each Group’s Average Pre-lab and Lab Report Scores…………………………………………………………..17 III. Regression Analysis of Each Group’s Average Planning Form and Lab Report Scores………………………………………….17 IV. Analysis of Covariance Results for Student Pre-lab and Planning Form Scores by Lab Investigation……………………………………………….25 V. Analysis of Covariance Results for Group Average Pre-lab Score and Lab Report Score by Lab Investigation……….……………………...26 VI. Analysis of Covariance Results for Group Average Planning Form Score and Lab Report Score by Lab Investigation………...………………27 VII. Analysis of Covariance Results for Student Average Pre-lab Score and Average Planning Form Score by Section……………………….…...35 VIII. Analysis of Covariance Results for Group Average Pre-lab Score and Average Lab Report Score by Section…….……………………….....36 IX. Analysis of Covariance Results for Group Average Planning Form Score and Average Lab Report Score by Section.………………………...37 X. Analysis of Covariance Results for Student Average Pre-lab Score and Average Planning Form Score by Teaching Assistant……………..……..…45 XI. Analysis of Covariance Results for Group Average Pre-lab Score and Average Lab Report Score by Teaching Assistant……………….…………46 XII. Analysis of Covariance Results for Group Average Planning Form Score and Average Lab Report Score by Teaching Assistant……….…………..47 vi Table Page XIII. Student Responses from Selected Questions on a Survey Given at the End of the Semester……………………………………………………….56 XIV. Sample of Student Comments on a Survey Given at the End of the Semester……………………………………………………………………...57 XV. Summary of the Results From the Analyses of Student Scores…………………….61 vii LIST OF FIGURES Title Page 1. Regression Analysis of Pre-lab and Planning Form Scores ……………………….....18 2. Regression Analysis of Pre-lab and Lab Report Scores ……………………………...20 3. Regression Analysis of Planning Form and Lab Report Scores………………………22 4. Analysis of Pre-lab and Planning Form Scores by Lab Investigation………………………………………………………………...28 5. Analysis of Pre-lab and Lab Report Scores by Lab Investigation……………………………………………………………………..30 6. Analysis of Planning Form and Lab Report Scores by Lab Investigation……………………………………………………………..32 7. Analysis of Pre-lab and Planning Form Scores by Section…………………………...38 8. Analysis of Pre-lab and Lab Report Scores by Section……………………………….40 9. Analysis of Planning Form and Lab Report by Section………………………………42 10. Analysis of Pre-lab and Planning Form Scores by Teaching Assistant………………………………………………………………48 11. Analysis of Pre-lab and Lab Report Scores by Teaching Assistant…………………………………………………………………………50 12. Analysis of Planning Form and Lab Report Scores by Teaching Assistant……………………………………………………………….52 13. Concept Map of a Summary of the Results from the Analyses of Student Scores………………………………………………………………...59 viii CHAPTER I INTRODUCTION Following recommendations made in the early 1990s, there has been an effort in science education to revise how science is taught. The American Association for the Advancement of Science (1990) suggested that to promote scientific reasoning“…science should be taught as science is practiced”. The National Research Council (1996) recommended that students learn science through scientific inquiry. Inquiry-based classes are preferred over traditional classes because students are engaged in learning science through an active process (NSTA, 1996). While there are many variations, in an open-ended inquiry-based laboratory, students formulate their own hypotheses, design a unique experiment, and conduct an investigation. Courses that include open-ended scientific investigations enhance students’ skills of observation and discovery, hypothesis formation, testing, and evaluating (Division of Undergraduate Science, Engineering, and Mathematics Education, 1990). To optimize learning, students must have the opportunity to design their own experiments and test their own hypotheses, especially in the laboratory (Lunsford, 2002). The Problem Because of the support for inquiry, educators are now focused on the most effective ways to implement this type of instructional format in the science classroom, especially in the laboratory. Two of the major problems reported by instructors of 1 inquiry-based laboratories are that some students do not participate enough and they lack background knowledge (Lawson, 2000). Other research supports the conclusion that a challenge to successfully facilitating an inquiry-based investigation is insufficient student preparation (Oliver-Hoyo et al., 2004 and Mazlo et al., 2002). Logically, if students are better prepared prior to attending laboratory, then they will be able to understand more of the rationale behind the processes being tested (Barnes and Thornton, 1998). It is especially important in inquiry-based laboratories that the students have the conceptual and procedural background they need to be able to formulate their own hypotheses and conduct open-ended investigations. Students who do not prepare are unable to fully engage in the design and completion of the investigation and this may reduce their opportunity for success in lab. In response, instructors attempt to encourage students to prepare for laboratory. The University of Toronto’s Teaching Assistants’ Training Programme (2005) advocates the use of pre-lab talks. They suggest that the first fifteen minutes of lab should be used by the instructor to review the background information, generally describe the lab through the use of a flow chart, and give directions for the proper use of equipment in the lab. However, the pre-lab talk method creates several problems. First, pre-lab talks are unlikely to be very effective in motivating students to prepare prior to lab. If the instructor is providing all of the information that the students need, why would students make an effort to come to class prepared? Second, it suggests that students will learn through a passive process as the instructor provides them information. This conflicts with research on how people learn (Donovan et al., 2000). Furthermore, pre-lab talks do not provide the students with enough time to carefully reflect on the information 2 provided, especially if it is conceptually challenging. A final drawback to the pre-lab talk method is that it takes time away from the students; they should be designing and conducting an experiment rather than being introduced to the lab investigation. Another method commonly used to encourage student preparation is to quiz the students at the beginning of class. Mazlo et al. (2002) found that students were more motivated to study prior to class if they knew that they were going to be quizzed and the quizzes would affect their grades. Assessment of the physics department at the University of Arkansas at Little Rock (2003) included a study on the effectiveness of prelab quizzes. Their assessment team analyzed student grades for each of the thirteen labs and reported that there was a significant positive correlation between pre-lab quiz scores and post-lab exams for ten of the experiments. From this, they concluded that overall the pre-lab quiz approach seemed to improve learning. However, this method causes one of the same problems as the pre-lab talks - it reduces the amount of time available for students to complete the lab investigation. To minimize this, instructors typically write quizzes composed of only simple multiple choice or short answer questions that are unlikely to require high-level conceptual thinking by the students. Sundberg et al. (2000) found that the traditional laboratory exams and quizzes are “meaningless” and these activities generally focus on facts rather than reasoning ability. Encouraging students to prepare by using a quiz will only motivate them to be able to answer those questions and may distract them from actually preparing to conduct the investigation. To avoid these issues, some instructors employ the use of pre-class exercises to help students prepare for lab. These instructors expect students to complete an activity or 3 series of activities prior to attending the laboratory class. Such activities vary in content and may include information on procedures, methods, equipment, facts, and concepts. At a minimum, pre-class activities provide the student with some experience with the investigation prior to class. According to the Graduate Student Instructor Teaching and Resource Center at the University of California in Berkeley (2005), there are several advantages of using prelab assignments over other forms of preparation. The advantages of a pre-lab assignment are 1) it better prepares students for the lab, 2) it helps the exercises run more smoothly, 3) it increases the student’s level of understanding, and 4) it makes it easier for the instructor to teach the theory behind the lab. The only disadvantage of using pre-lab assignments is the time it takes to write and evaluate them. Educators at other universities have implemented the use of pre-labs. One instructor of an introductory chemistry course prohibited students from entering the lab room unless they completed the pre-lab assignment (The University of Michigan, 2005). In a physics course at Armstrong Atlantic State University, pre-lab exercises comprised twenty percent of the student’s grade (Mullenax, 2002). Faculty teaching an electronic design course at the University of South Carolina required a student to repeat a lab if the pre-lab exercise was not satisfactory (Hudgins, 2002). In a computer science class at Duke University, the pre-lab assignments were optional in 1999 (Astrachan, 1999) but later required (Duvall, 2005). Previous Research Instructors who promote the use of pre-class activities do so because they think that it is an effective way to motivate students to prepare for class, which is especially 4 crucial for inquiry-based labs. Although educators may have good reason to feel confident in this assumption, few researchers have reported the effectiveness of pre-class activities. Kirk and Layman (1996) conducted research on improving student understanding in an introductory chemistry course. Of the students interviewed (n=56), they found that 41% “felt better prepared” when they used a pre-lab guide for lab preparation. In another introductory chemistry course, Barnes and Thornton (1998) conducted research on pre-lab effectiveness using both quantitative and qualitative methods. They found no significant correlation between performance on pre-laboratory questions and the lab reports or the mid-semester exams. However, they found that students (n=63) felt that using the pre-laboratory questions made writing the lab report easier. This group of students enjoyed lab classes more and felt more confident in their lab work. Similar results were reported by Wyatt (2003) from Western Kentucky University. He implemented the use of online pre-labs in his biology course in an attempt to improve the level of student preparation for the laboratories. The data he collected failed to show any statistical difference in learning outcomes between students who used the pre-labs and students that did not. However, through an end of the semester survey, more than 95% of about 300 students indicated satisfaction with the pre-lab exercises. These students thought that using the pre-labs probably improved their lab skills and their grade. Wyatt concluded that student satisfaction with the implementation of pre-lab exercises is an indication of the importance of using pre-class activities in the laboratory. Instructors of an undergraduate physics laboratory also wanted to test the usefulness of pre-lab preparation. Johnstone et al. (1998) studied students (n=95) 5 participating in four laboratories, two with pre-labs and two without pre-labs. First, they collected student responses on a survey and analyzed student attitudes concerning the pre-labs. They reported that overall students favored using the pre-labs. These researchers also compared mean scores on the post-lab assessment of students who used pre-labs to those that did not. Their results indicated that the students that participated on the pre-labs achieved significantly higher levels of performance on the post-lab assessment. They concluded that the students’ understanding of these laboratories was enhanced by the use of pre-labs. Generally, the previous research indicates that students perceive that pre-lab exercises are beneficial. Students who complete pre-lab exercises feel better prepared and believe that these activities help them perform well during the investigation and on laboratory assignments (Kirk and Layman, 1996; Barnes and Thornton, 1998, Wyatt, 2003). Moreover, there is some indication that pre-lab exercises may correlate with an increase in student performance on post-lab assessment (Johnstone, et al., 1998). However, from such limited research and ambivalent findings, it is difficult to draw definitive conclusions on the effectiveness of preliminary activities on student performance and success in lab. The purpose of this study is to extend the research in this area. Course Design The pre-class method of preparation is used in the introductory biology laboratories at Oklahoma State University. This class is a first-year course offered for both science majors and non-majors. Students attend one of four or five lecture sections, 6 typically taught by different lecture instructors. Students are also assigned to lab sections of 21-24 students. During the semester, students conduct fourteen laboratory investigations. For each laboratory session, the lab manual provides students with background information and a question for investigation (French, 2004). Based on these, the students must then propose a hypothesis, design methods to test that hypothesis, conduct their experiment, and report their results. During the lab period, the students work in groups of three to four members to complete the investigation. Students collaborate to write a group hypothesis and conduct an experiment. To report their results and answer the question, each group writes a lab report. The lab report includes introduction, methods, results, and discussion sections. The majority of the points earned by each student in laboratory are from the lab report scores. A copy of the grading scheme for the lab report can be found in the appendix (Appendix B). Students are expected to prepare individually prior to class. To encourage and guide this, the course employs two activities. The first activity is a required assignment called a planning form. Here, the individual student must write a hypothesis, describe the experimental design, and make predictions on possible experimental outcomes. A smaller portion of the planning form asks questions specific to that lab investigation and may address either procedural or conceptual information. To help students complete each planning form, a second activity, the pre-lab exercise, is offered for extra credit. These activities vary depending on the lab topic and provide the students with either the procedural or conceptual information specific to the investigation that they should know 7 prior to class. An example of the planning form with the pre-lab activities can be found in the appendix (Appendix A). Objectives of the Study Based on casual observations, it seems that the students who are less engaged in the investigation and have lower lab report scores are those that are the least prepared. To test the validity of this association, I designed a study to determine whether a relationship exists between student performances on pre-class assignments and the laboratory assessment. I addressed the following questions: • Does participation in preliminary exercises lead to higher performance in the laboratory? Specifically, I sought to answer the following: o Do the students that perform well on pre-lab exercises score higher on the planning forms? o Do student groups that perform well on the pre-lab exercises score higher on the lab report scores? o Do student groups that perform well on planning forms score higher on the lab reports? • What other factors affect student performance in lab? Specifically, I sought to answer the following: o Does student performance vary with the lab investigation? o Does student performance vary with the section? o Does student performance vary with the teaching assistant? • What are the students’ perceptions of the laboratory in our introductory biology class? 8 CHAPTER II METHODS Subjects This study included data on students enrolled in four lecture sections of the introductory biology course at Oklahoma State University. For the performance analysis, I used grades from every student who participated in at least one laboratory in the spring semester of 2004. For the perception analysis, I used student responses on a survey provided at the end of the course in the spring semester of 2005. This only included students who remained in the course for the duration of the semester. Analyses of Student Grades In the introductory biology course, teaching assistants record student laboratory grades in WebCT. The course coordinator, Dr. Donald French, provided me with anonymous student data. For each lab investigation, teaching assistants recorded three scores for each student: a pre-lab, planning form, and lab report score. The data from WebCT also included the section in which each student was enrolled, the group to which each student belonged, and the teaching assistant who taught each student. Thus I analyzed grades according to the student, group, section, teaching assistant, and lab investigation. I analyzed grades of students from only one semester because the sample size (n=764) was sufficient to provide adequate data while avoiding any confounding effect of 9 semester, which may introduce additional variation in students and teaching assistants. I measured student performance based on the scores each student earned on pre-labs, planning forms, and lab reports for each of the fourteen lab investigations during the semester. Regression Analyses To analyze the students’ grades, I used SAS software (SAS Institute, 2002). To address my questions, I examined the following relationships: pre-labs and planning forms, pre-labs and lab reports, and planning forms and lab reports. I used regression analysis to determine the presence of a linear relationship and the predictive abilities of these models. I used analysis of variance (ANOVA) to evaluate the significance of the regression models. This also provided the coefficient of determination, or r-square value, for each model. The r-square values measure the relative strength of the regression models by reflecting the proportion of the total variation associated with the regression of the dependent variable on the independent variable. To determine if pre-lab participation helped students prepare, I analyzed pre-lab and planning form scores. If pre-labs were beneficial, then students who completed and/or scored higher on the pre-lab activities should have scored higher on their planning forms. I performed regression analysis of each student’s average planning form score on his/her average pre-lab score. I averaged each student’s scores over the fourteen lab investigations to avoid inflating the sample with multiple pre-lab and planning form scores from the same student. I applied an ANOVA test to determine the significance of the regression model. I compared the relationship of pre-lab and planning form scores 10 using the coefficient of determination (r-square) and tested whether the slope of the regression line was equal to zero. To determine if preparation helped students perform better in lab, I analyzed scores on pre-class activities (pre-labs and planning forms) and lab report scores. If prelabs were beneficial, then student groups that completed and/or scored higher on the prelab activities should have scored higher on the lab report. To compare the pre-lab activities to the lab report score, I averaged the students’ pre-lab scores to provide a group pre-lab score for each investigation because the lab report is completed by the group. To calculate the group pre-lab score, I averaged the pre-lab scores of all of the group members by dividing the total points earned on the pre-lab by all members of the group who participated in writing the lab report by the number of participants. Thus, the group pre-lab score reflected both how many students participated and how well each student performed on the pre-lab activity. For the overall description of the relationship, I then averaged each group’s pre-lab scores and lab report scores over the fourteen lab investigations and performed regression analysis. I averaged each group’s scores to avoid inflating the sample with multiple scores from the same group. I also analyzed the second pre-class activity, the planning form, in relation to the lab report. If planning forms were beneficial, then student groups that performed well on planning forms should have produced higher lab report scores. I repeated the same process on this regression as I did for the regression of the lab report scores on the pre-lab scores. I applied ANOVA on each pre-class and lab report regression to determine the significance of these models. I compared the relationship of pre-lab and planning form 11 scores to lab report scores using the coefficient of determination (r-square) and tested whether the slopes of the regression lines were equal to zero. Analyses of Covariance After I performed these preliminary analyses, I discovered that the regression models accounted for little of the variation in student grades, demonstrated by low rsquare values. This led me to test for other possible factors contributing to the variation in student scores. To test these, I performed separate analyses of covariance (ANCOVA) for three different classification variables: lab investigation, section, and teaching assistant. I used ANCOVA to maximize the explained variance and determine which factors, or classification variables, may be increasing the variability in the data. The ANCOVA test is comparable to multiple regression with qualitative variables representing the category variables. The ANCOVA tests also provided the r-square values for the models based on the classification variables. To produce graphs for each classification group, I used the least square means (LSmeans) of the dependent variable at the minimum and maximum values of the independent variable. I used this method to produce the ANCOVA graphs to show the general trends of the data. To determine if the lab investigation had an effect on student scores, I applied ANCOVA. For the analysis of pre-lab and planning form scores, I included all of the students who submitted a planning form for the investigation, regardless of whether they participated on the pre-lab exercises. To test the relationship of the lab report and the pre-lab score in relation to the investigation, I used the group pre-lab score. I used the average pre-lab score for each group because the lab report score is earned by the group members present for the investigation. I repeated the same procedure to analyze the 12 group average planning form and lab report score for each investigation. Unlike the general analyses, I did not average the students’ or groups’ scores over the investigations because the scores needed to be discrete to test for the effect of investigation as a classification variable. This resulted in very large numbers of sample points included in these analyses. To determine if the section had an effect on student scores, I applied ANCOVA. For the analysis of pre-lab and planning form scores, I used the average of each of the student’s pre-lab and planning forms scores across the investigations so that the sample would not be inflated with multiple points from the same student. I repeated the analyses including the classification variable of section on the group average pre-lab and lab report scores and on group average planning form and lab report scores. To determine if the teaching assistant had an effect on student scores, I applied ANCOVA. For the analysis of pre-lab and planning form scores, I used the student averages as I did with the section classification. I repeated these analyses on group average pre-lab and lab report scores and on group average planning form and lab report scores. With all three ANCOVA analyses, I evaluated the classification effects using the coefficient of determination (r-square) and tested whether the slopes of the regression lines were equal to zero. Analyses of the Student Survey In addition to grade analyses, I analyzed student perceptions of the biology course at Oklahoma State University. I included quantitative and qualitative analyses to provide insight into student opinions concerning their performance and success in laboratory. 13 I reviewed student responses on a survey given to the biology students after their final examination. They were asked to express their opinions on a five point scale by how strongly they agreed (1) or disagreed (5) with a set of statements. The students recorded their responses on a scantron sheet. I gathered the scantron sheets from each of the four lecture sections and tallied the responses using a scanner. Then I determined the number of respondents and the percentage of each response on the questions relevant to laboratory. Some of the questions on the survey referred to inquiry-based investigations, pre-class activities and preparation for lab, group work, teaching assistants, and the course website. A copy of the entire survey can be found in the appendix (Appendix C). The questions of interest can be found in Table XIII. Students were also given an opportunity to provide open-ended responses concerning what they did or did not enjoy about the course. I reviewed these written responses and grouped them by topic. I selected a small subset of these responses to demonstrate the differences in opinion students hold concerning the same aspect of the course. I included these data to provide insight into specific student perceptions concerning the laboratories. 14 CHAPTER III RESULTS The purpose of this study was to investigate student success in an inquiry-based laboratory based on their performance on pre-class activities and the in-class lab report. I attempted to answer the following questions: • Does participation in preliminary exercises lead to higher performance in the laboratory? Specifically, I sought to answer the following: o Do the students that perform well on pre-lab exercises score higher on the planning forms? o Do student groups that perform well on the pre-lab exercises score higher on the lab report scores? o Do student groups that perform well on planning forms score higher on the lab reports? • What other factors affect student performance in lab? Specifically, I sought to answer the following: o Does student performance vary with the lab investigation? o Does student performance vary with the section? o Does student performance vary with the teaching assistant? • What are the students’ perceptions of the laboratory in our introductory biology class? 15 Question 1: Does participation in preliminary exercises lead to higher success in the laboratory? General Regression Models Each of the regression models (pre-lab and planning form, pre-lab and lab report, planning form and lab report) was significant. Each model showed a significant relationship between the independent and dependent variables (each p<0.0001). Each regression line had a slope significantly different than zero (each p<0.0001). However, the coefficient of determination was relatively low for each model (Table I, II, and III). The relationship between pre-lab and planning form scores had the highest r-square value (0.1576) and the relationship between planning form and lab report scores had the lowest (0.0965). Therefore, although the linear relationships were significant, this may have been a result of the large sample sizes. The relatively low r-square values reflect that although there were significant relationships between the scores, most of the variation was not accounted for by these models. Graphs of the regression lines are shown in Figures 1, 2, and 3. 16 TABLE I REGRESSION ANALYSIS OF EACH STUDENT’S AVERAGE PRE-LAB AND PLANNING FORM SCORES Source n F-value p-value H0: slope = 0 rejection p-value r2 Model 757 141.25 <0.0001 <0.0001 0.1576 TABLE II REGRESSION ANALYSIS OF EACH GROUP’S AVERAGE PRE-LAB AND LAB REPORT SCORES Source n F-value p-value H0: slope = 0 rejection p-value r2 Model 206 31.40 <0.0001 <0.0001 0.1334 TABLE III REGRESSION ANALYSIS OF EACH GROUP’S AVERAGE PLANNING FORM AND LAB REPORT SCORES Source n F-value p-value H0: slope = 0 rejection p-value r2 Model 203 21.48 <0.0001 <0.0001 0.0965 17 Figure 1. Regression Analysis of Pre-lab and Planning Form Scores (n=757, r2 = 0.1576). The model includes each student’s average planning form regressed on his/her average pre-lab score. The scores are averaged over all fourteen lab investigations. 18 19 Figure 1 Figure 2. Regression Analysis of Pre-lab and Lab Report Scores (n=206, r2 = 0.1334). The model includes each group’s average lab report score regressed on their average prelab score. The scores are averaged over all fourteen lab investigations. 20 21 Figure 2 Figure 3. Regression Analysis of Planning Form and Lab Report Scores (n=203, r2 = 0.0965). The model includes each group’s average lab report regressed on their average planning form score. The scores are averaged over all fourteen lab investigations. 22 23 Figure 3 Question 2: What other factors affect student performance in lab? ANCOVA Including Lab Investigation Each of the three models (pre-lab and planning form, pre-lab and lab report, planning form and lab report) was significant according to ANCOVA output (p<0.0001). The majority of the regression lines based on the classification of lab investigation was significantly different from zero (p-values <0.05). However, the coefficients of determination were also relatively low for each model (Table IV, V, and VI). Moreover, the r-squared values were nearly the same as those from the previous models without the classification of lab investigation. Similar to those models, the highest r-square value was with the model of pre-lab and planning form (0.1462) and the lowest r-square value was with the model of planning forms and lab report (0.0963). These results indicated that the inclusion of the lab investigation did not reduce the amount of unaccounted for variation between student scores when compared to the general regression models. The significance of these analyses of covariance is likely attributed to the large sample sizes. In other words, there was a relationship between the scores but the relationships did not vary with the lab investigations. Graphs of the relationships using the LSmeans are shown in Figures 4, 5, and 6. 24 TABLE IV ANALYSIS OF COVARIANCE RESULTS FOR STUDENT (N=757) PRE-LAB AND PLANNING FORM SCORES BY LAB INVESTIGATION Sample Size H0: slope = 0 rejection p-value r2 Overall Model 9370 <0.0001 0.1462 Lab 1 Lab 2 Lab 3 Lab 4 Lab 5 Lab 6 Lab 7 Lab 8 Lab 9 Lab 10 Lab 11 Lab 12 Lab 13 Lab 14 658 692 697 677 685 702 675 671 673 642 667 665 655 611 0.0220 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 0.0004 <0.0001 <0.0001 <0.0001 0.1211 0.0165 0.0788 0.0678 0.1390 0.0786 0.0391 0.1336 0.1242 0.1087 0.0137 0.0724 0.0430 0.0316 0.0067 Data Set 25 TABLE V ANALYSIS OF COVARIANCE RESULTS FOR GROUP (N=206) AVERAGE PRE-LAB SCORE AND LAB REPORT SCORE BY LAB INVESTIGATION Sample H0: slope = 0 r2 Data Set Size rejection p-value Overall Model 2834 <0.0001 0.1067 Lab 1 Lab 2 Lab 3 Lab 4 Lab 5 Lab 6 Lab 7 Lab 8 Lab 9 Lab 10 Lab 11 Lab 12 Lab 13 Lab 14 206 204 203 204 203 202 203 203 203 202 202 202 203 194 0.0028 0.0005 0.0007 <0.0001 0.4161 0.0390 0.0412 0.0035 0.0033 0.0033 0.0004 0.2435 0.0028 0.9462 0.0268 0.0521 0.0450 0.1099 0.0044 0.0205 0.0200 0.0559 0.0322 0.0300 0.0663 0.0118 0.0485 0.0000 26 TABLE VI ANALYSIS OF COVARIANCE RESULTS FOR GROUP (N=206) AVERAGE PLANNING FORM SCORE AND LAB REPORT SCORE BY LAB INVESTIGATION Sample Size H0: slope = 0 rejection p-value r2 Overall Model 2834 <0.0001 0.0963 Lab 1 Lab 2 Lab 3 Lab 4 Lab 5 Lab 6 Lab 7 Lab 8 Lab 9 Lab 10 Lab 11 Lab 12 Lab 13 Lab 14 206 204 203 204 203 202 203 203 203 202 202 202 203 194 0.2941 0.0002 0.0087 <0.0001 0.0743 0.0020 0.0051 0.2456 0.0857 0.0205 0.3986 0.0322 0.8230 0.6580 0.0041 0.0585 0.0266 0.1096 0.0214 0.0456 0.0374 0.0088 0.0109 0.0185 0.0038 0.0394 0.0003 0.0012 Data Set 27 Figure 4. Analysis of Pre-lab and Planning Form Scores by Lab Investigation (n=9370, r2 = 0.1462). The model includes student scores of pre-labs and planning forms with each line representing a different lab investigation. The scores were not averaged. Lines were produced using the LSmeans. 28 29 Figure 4 Figure 5. Analysis of Pre-lab and Lab Report Scores by Lab Investigation (n=2834, r2 = 0.1067). The model includes the group’s average pre-lab score with their lab report score. Each line represents a different lab investigation. Lines were produced using the LSmeans. 30 31 Figure 5 Figure 6. Analysis of Planning Form and Lab Report Scores by Lab Investigation (n=2834, r-square 0.0963). The model includes the group’s average planning form score and their lab report score. Each line represents a different lab investigation. Lines were produced using the LSmeans. 32 33 Figure 6 ANCOVA Including Section The ANCOVA results demonstrated that each of the three models (pre-lab and planning form, pre-lab and lab report, planning form and lab report) was significant (p<0.0001). Although some of the slopes were significantly different than zero, many were not and the results varied among sections (Tables VII, VIII, and IX). The models with section included had much higher r-square values than the previous models. The highest r-square was with the model of pre-lab and planning form scores (0.4779) and the lowest r-square was with the model of pre-lab and lab report (0.4091). These coefficients of determination demonstrated that the strength of the relationships between the students’ scores varied greatly among sections. Moreover, the ANCOVA analyses with the inclusion of section were very successful in reducing the amount of unaccounted variation as compared to the general regression models. Graphs of the relationships using the LSmeans are shown in Figures 7, 8, and 9. 34 TABLE VII ANALYSIS OF COVARIANCE RESULTS FOR STUDENT (N=756) AVERAGE PRE-LAB SCORE AND AVERAGE PLANNING FORM SCORE BY SECTION Sample Ho: slope = 0 r2 Size rejection p-value Overall Model 756 <0.0001 0.4779 Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7 Section 8 Section 9 Section 10 Section 11 Section 12 Section 13 Section 14 Section 15 Section 16 Section 17 Section 18 Section 19 Section 20 Section 21 Section 22 Section 23 Section 24 Section 25 Section 26 Section 27 Section 28 Section 29 Section 30 Section 31 Section 32 Section 33 Section 34 22 22 23 22 20 24 21 24 22 22 22 24 23 24 24 25 22 23 23 21 20 23 23 24 24 24 22 22 19 23 21 23 21 21 0.5034 0.1693 0.0017 0.1638 0.0187 0.0001 0.0482 0.9175 0.3185 0.2202 0.1597 0.1355 0.0008 0.1358 0.0106 0.1876 0.0009 0.1060 0.1679 <0.0001 0.0794 0.0003 0.0002 0.0289 0.0009 <0.0001 <0.0001 0.0311 <0.0001 0.0549 0.0042 0.0233 <0.0001 <0.0001 35 0.0872 0.1623 0.4180 0.2165 0.3014 0.3132 0.1379 0.0022 0.1282 0.0960 0.0608 0.1075 0.3271 0.1176 0.2744 0.0589 0.3118 0.1496 0.2096 0.4822 0.1497 0.4011 0.7558 0.4058 0.2830 0.2821 0.3491 0.3293 0.5914 0.0599 0.4277 0.4065 0.2765 0.3917 TABLE VIII ANALYSIS OF COVARIANCE RESULTS FOR GROUP (N=203) AVERAGE PRE-LAB SCORE AND AVERAGE LAB REPORT SCORE BY SECTION Overall Model Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7 Section 8 Section 9 Section 10 Section 11 Section 12 Section 13 Section 14 Section 15 Section 16 Section 17 Section 18 Section 19 Section 20 Section 21 Section 22 Section 23 Section 24 Section 25 Section 26 Section 27 Section 28 Section 29 Section 30 Section 31 Section 32 Section 33* Section 34 r2 Ho: slope = 0 rejection p-value <0.0001 0.4091 0.7657 0.6354 0.1429 0.4298 0.0787 0.9827 0.7419 0.5617 0.3919 0.1584 0.2374 0.2646 0.0021 0.6807 0.1059 0.6816 0.3990 0.1595 0.6416 <0.0001 0.3607 0.0722 0.0673 0.7241 0.0082 0.1003 0.1276 0.4213 <0.0001 0.1586 0.4714 0.3421 0.5408 0.7052 0.0150 0.0408 0.2178 0.0364 0.0815 0.0000 0.0070 0.0205 0.1275 0.2191 0.1658 0.0627 0.1333 0.0091 0.1010 0.0113 0.0301 0.1681 0.0570 0.3174 0.0563 0.0670 0.1920 0.0319 0.2979 0.0842 0.0778 0.0503 0.4061 0.1273 0.1057 0.1265 0.0051 0.0063 *All sections included data from six groups with the exception of number 33, with only five groups. 36 TABLE IX ANALYSIS OF COVARIANCE RESULTS FOR GROUP (N=203) AVERAGE PLANNING FORM SCORE AND AVERAGE LAB REPORT SCORE BY SECTION Ho: slope = 0 r2 rejection p-value Overall Model <0.0001 0.4607 Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7 Section 8 Section 9 Section 10 Section 11 Section 12 Section 13 Section 14 Section 15 Section 16 Section 17 Section 18 Section 19 Section 20 Section 21 Section 22 Section 23 Section 24 Section 25 Section 26 Section 27 Section 28 Section 29 Section 30 Section 31 Section 32 Section 33* Section 34 0.8869 0.4225 0.1758 0.0464 <0.0001 0.4581 0.0386 0.9593 0.6921 0.6631 0.1498 0.5354 <0.0001 0.1386 0.9338 0.0769 0.1161 0.8067 0.3462 <0.0001 0.9155 0.7636 0.9407 0.7023 0.0857 0.0018 0.7324 0.3562 <0.0001 0.0060 0.5010 0.5090 0.0782 0.1775 0.0031 0.1065 0.1697 0.2120 0.4332 0.0474 0.2515 0.0001 0.0249 0.0191 0.2249 0.0176 0.3701 0.1079 0.0002 0.1914 0.0953 0.0046 0.2133 0.5594 0.0007 0.0017 0.0003 0.0341 0.1146 0.2791 0.0036 0.0604 0.3246 0.4431 0.0842 0.0558 0.0385 0.0730 *All sections included data from six groups with the exception of number 33, with only five groups. 37 Figure 7. Analysis of Pre-lab and Planning Form Scores by Section (n=756, r2 = 0.4779). The model includes the student’s average pre-lab score and his/her average planning form score. Each line represents scores from students in different sections. Lines were produced using the LSmeans. 38 39 Figure 7 Figure 8. Analysis of Pre-lab and Lab Report Scores by Section (n=203, r2 = 0.4091). The model includes the group’s average pre-lab and average lab report scores. Each line represents scores from groups in different section. Lines were produced using the LSmeans. 40 41 Figure 8 Figure 9. Analysis of Planning Form and Lab Report Scores by Section (n=206, r2 = 0.4607). The model includes the group’s average planning form and average lab report scores. Each line represents scores from groups in different sections. Lines were produced using the LSmeans. 42 43 Figure 9 ANCOVA Including Teaching Assistant Each of the three models (pre-lab and planning form, pre-lab and lab report, planning form and lab report) was significant according to ANCOVA results (p<0.0001). At a significance level of p<0.05, the majority of the regression lines of student scores based on the teaching assistant had slopes not equal to zero. All but one had a nonzero slope on the model of pre-lab and planning form scores (Table X), but the results from this test varied greatly for the pre-class and lab report models (Table XI and XII). The rsquare value was highest for the pre-lab and planning form model (0.4319) and lowest for the pre-lab and lab report model (0.2885). The coefficients of determination demonstrate that the strength of the relationships between student scores varied greatly among the teaching assistants. These results suggest that the teaching assistant had a significant effect on student grades and it was useful to include this factor in an ANCOVA test. This method reduced the amount of unaccounted variation compared to the general regression analyses and the analyses including the lab investigation. Graphs of the relationships using the LSmeans are shown in Figures 10, 11, and 12. 44 TABLE X ANALYSIS OF COVARIANCE RESULTS FOR STUDENT (N=756) AVERAGE PRE-LAB SCORE AND AVERAGE PLANNING FORM SCORE BY TEACHING ASSISTANT (TA) Sample Size Ho: slope = 0 rejection p-value r2 Overall Model 756 <0.0001 0.4319 TA 1 TA 2 TA 3 TA 4 TA 5 TA 6 TA 7 TA 8 TA 9 TA 10 TA 11 TA 12 TA 13 TA 14 TA 15 TA 16 TA 17 43 42 46 48 47 44 44 43 47 48 44 47 40 44 46 48 45 0.0007 0.0072 0.2741 0.0098 0.0142 0.0466 <0.0001 <0.0001 0.0025 <0.0001 <0.0001 0.0227 <0.0001 0.0003 0.0003 0.0016 <0.0001 0.2284 0.2460 0.0875 0.2281 0.2980 0.0798 0.2618 0.4296 0.1105 0.2709 0.3962 0.1390 0.3384 0.4220 0.2172 0.1575 0.2476 45 TABLE XI ANALYSIS OF COVARIANCE RESULTS FOR GROUP (N=203) AVERAGE PRE-LAB SCORE AND AVERAGE LAB REPORT SCORE BY TEACHING ASSISTANT (TA) Ho: slope = 0 rejection p-value r2 Overall Model <0.0001 0.2885 TA 1 TA 2 TA 3 TA 4 TA 5 TA 6 TA 7 TA 8 TA 9 TA 10 TA 11 TA 12 TA 13* TA 14 TA 15 TA 16 TA 17 <0.0001 0.4460 0.2753 0.4296 0.2735 0.1167 0.1565 0.0172 0.0457 0.0043 0.1681 0.2631 0.0017 0.0787 0.8760 0.0366 0.8790 0.1690 0.0153 0.0399 0.0451 0.0925 0.1463 0.0420 0.1571 0.1105 0.1659 0.0301 0.0414 0.0923 0.1143 0.0006 0.0518 0.0010 * All teaching assistants included data from twelve groups with the exception of number 13, with only eleven groups. 46 TABLE XII ANALYSIS OF COVARIANCE RESULTS FOR GROUP (N=203) AVERAGE PLANNING FORM SCORE AND AVERAGE LAB REPORT SCORE BY TEACHING ASSISTANT (TA) Ho: slope = 0 rejection p-value r2 Overall Model <0.0001 0.3667 TA 1 TA 2 TA 3 TA 4 TA 5 TA 6 TA 7 TA 8 TA 9 TA 10 TA 11 TA 12 TA 13* TA 14 TA 15 TA 16 TA 17 <0.0001 0.0429 0.1375 0.2556 0.1185 0.2328 0.2330 0.4944 0.0255 0.008 0.3090 0.8833 0.0010 0.0867 0.1859 <0.0001 0.0630 0.5933 0.0965 0.0658 0.0831 0.1674 0.0753 0.0265 0.0115 0.1230 0.2023 0.0146 0.0006 0.0898 0.0966 0.0382 0.2680 0.1342 * All teaching assistants included data from twelve groups with the exception of number 13, with only eleven groups. 47 Figure 10. Analysis of Pre-lab and Planning Form Scores by Teaching Assistant (n=756, r2 = 0.4319). The model includes the student’s average pre-lab score and his/her average planning form score. Each line represents scores from students instructed by different teaching assistants. Lines were produced using the LSmeans. 48 49 Figure 10 Figure 11. Analysis of Pre-lab and Lab Report Scores by Teaching Assistant (n=203, r2 = 0.2885). The model includes the group’s average pre-lab score and average lab report score. Each line represents scores from groups instructed by different teaching assistants. Lines were produced using the LSmeans. 50 51 Figure 11 Figure 12. Analysis of Planning Form and Lab Report Scores by Teaching Assistant (n=203, r2 = 0.3667). The model includes the group’s average planning form and average lab report score. Each line represents scores from groups instructed by different teaching assistants. Lines were produced using the LSmeans. 52 53 Figure 12 Question 3: What are the students’ perceptions of the laboratory in our introductory biology class? Analyses of the Student Survey Student responses (minimum response n= 628) to a selection of questions on the survey are in Table XIII. Most students (76%) agreed that they felt confident with their ability to develop a hypothesis and design an experiment, but would prefer (67%) to have an experiment provided rather than designing their own. Students (69%) generally liked working with a group and most students (65%) agreed that their group members explained lab procedures if they did not understand a concept. Only a fourth of the students agreed, however, that individuals did not have to learn the lab procedures because the group members would perform the experiment for them. The majority of the students (66%) felt that they were well prepared for lab each week and most (77%) indicated that pre-lab exercises helped them prepare. Most students reported that they regularly prepared for lab by completing pre-labs (72%) and planning forms (91%). However, some of the students (28%) responded that they rarely understood what each week’s lab was about even after completing the pre-lab and planning form. Most students (82%) also said that their teaching assistant explained the lab procedures before class. A selection of student responses on the open-ended portion of the survey is found on Table XIV. Students commented on a variety of topics including inquiry, the preclass activities, working in groups, teaching assistants, and other laboratory resources. Interestingly, there were students that strongly supported and students that strongly opposed each of these aspects of the course. These example quotes demonstrate how the 54 students enrolled in the same course at the same time often have very different experiences. 55 TABLE XIII STUDENT RESPONSES FROM SELECTED QUESTIONS ON A SURVEY GIVEN AT THE END OF THE SEMESTER The number of students is given in parentheses. n A – Strongly B – Agree Agree 8. I used the WWW site often. 639 35% (223) 42% (268) C –Neither agree D- Disagree nor disagree 12% (78) 9% (56) E – Strongly Disagree 2% (14) 18. I wish other courses would allow me to work with a group. 638 32% (205) 37% (239) 17% (107) 10% (61) 4% (26) 31. I felt that I was well prepared as I went into lab each week. 628 22% (141) 43% (272) 19% (120) 12% (78) 3% (17) 32. I felt that my group members were well prepared for lab each week. 629 18% (114) 41% (256) 21% (132) 14% (87) 6% (40) 33. When I did not understand a lab procedure, my group members explained it. 629 19% (122) 46% (292) 16% (102) 12% (78) 6% (35) 34. I did not have to learn all the lab procedures because my group members did it. 630 6% (35) 20% (125) 22% (139) 37% (236) 15% (95) 35. The pre-labs helped me prepare for lab. 628 29% (181) 48% (303) 12% (74) 8% (52) 3% (18) 36. I regularly prepared for lab by doing the pre-lab. 630 36% (229) 36% (228) 12% (75) 12% (73) 4% (25) 37. I regularly completed my planning form. 629 61% (384) 30% (190) 5% (29) 3% (16) 2% (10) 38. I regularly received full credit on my planning forms. 627 30% (191) 40% (251) 14% (85) 13% (81) 3% (19) 39. I rarely understood what each week’s lab was about even after I completed my planning form and pre-labs. 628 7% (44) 21% (129) 19% (121) 39% (248) 14% (86) 40. I feel confident with my ability to develop a hypothesis and design an experiment. 628 29% (182) 47% (293) 17% (108) 6% (37) 1% (8) 41. I would rather be given an experiment to perform than have to design my own. 629 30% (186) 37% (231) 17% (109) 11% (70) 5% (33) 43. My TA explained all the procedures before class. 629 46% (288) 36% (226) 10% (61) 56 6% (40) 2% (14) TABLE XIV SAMPLE OF STUDENT COMMENTS ON A SURVEY GIVEN AT THE END OF THE SEMESTER Topic Please list up to three aspects of the course you liked most and why: Please list up to three aspects you would change and how and why: Inquirybased labs “The lab experiments because they further my understanding of the topic.” “Lab – helped me develop my experimental skills, developing hypotheses, etc.” “Lab – seeing how biology relates to real life.” “I really didn’t like conducting our own experiments and would rather follow directions.” “The labs are tedious and are not helpful to understanding the material.” “The labs are often too complicated” Pre-class activities “Pre-labs – helped you understand better.” “Pre-labs prepared me for lab.” “Pre-lab should be required.” “I didn’t like the planning forms.” Group work “Working in groups – it helped when there were many minds over just one.” “My lab group – because we were all cooperative and helped each other.” “The group is helpful at times, but I like individual effort too.” “Sometimes group members didn’t come and it made lab longer.” Teaching Assistant “All of the TAs.” “TAs in lab need to be more helpful.” “Some TA grading was not consistent; some TAs were extremely lenient in comparison to others.” “My lab TA – she did a wonderful job on helping us understand if we were confused.” Resources “The website was very helpful.” “TA in the LRC is willing to help when you do not get it.” 57 “Planning forms took a long time to complete.” “Sometimes the (on-line) tutorials would not work.” “Be willing to help when we come to the LRC.” Summary of Results The purpose of this study was to determine which factors affect student performance in an inquiry-based laboratory, with specific regard to student preparation. This project included over seven hundred students’ grades on lab reports and pre-class activities (pre-labs and planning forms). I tested the following relationships using regression analyses: pre-lab and planning form scores, pre-lab and lab report scores, planning form and lab report scores. There were weak, statistically significant relationships between the independent and dependent variables of student scores, identified by the relatively low r-square values in these models. I also tested the strength of the relationships between student scores with the inclusion of the lab investigation, section, and teaching assistant using analyses of covariance. The coefficients of determination were higher with the inclusion of either section or teaching assistant, suggesting that these models provided better descriptions of the relationships. Also, the r-square values were highest with the relationship of pre-lab to planning form for each of the ANOVA and ANCOVA models, suggesting an effect of group collaboration on student scores. A summary of these results can be found in Table XIII. Despite the relatively low r-square values in the general models, students reported that they felt prepared after completing the pre-class activities and they were confident with their abilities to conduct an inquiry-based investigation. A conceptual overview of the factors affecting student performance can be found on Figure 13. This concept map shows the connections between pre-lab, planning form, and lab report scores along with the effects of lab investigation, section, teaching assistant, and group collaboration. 58 Figure 13. Concept Map of a Summary of the Results from the Analyses of Student Scores. 59 60 Figure 13 TABLE XV SUMMARY OF THE RESULTS FROM THE ANALYSES OF STUDENT SCORES Model r- square value General Regression Pre-lab and Planning Form Scores Pre-lab and Lab Report Scores Planning Form and Lab Report Scores 0.1576 0.1334 0.0965 Classification 1: Lab Investigation Pre-lab and Planning Form Scores Pre-lab and Lab Report Scores Planning Form and Lab Report Scores 0.1462 0.1067 0.0963 Classification 2: Section Pre-lab and Planning Form Scores Pre-lab and Lab Report Scores Planning Form and Lab Report Scores 0.4779 0.4091 0.4607 Classification 3: Teaching Assistant Pre-lab and Planning Form Scores Pre-lab and Lab Report Scores Planning Form and Lab Report Scores 0.4319 0.2885 0.3667 61 CHAPTER IV DISCUSSION Findings General Regression Models Based on my regression analyses, it appears that students who performed well on the pre-lab were more likely to perform well on the planning forms and student groups who performed well on the pre-labs or the planning forms were more likely to perform well on the lab reports. Thus, preparation may contribute to student success in the laboratory. These results are unlike those reported by Barnes and Thornton (1998). They did not find any significant correlation between performance on pre-laboratory questions and laboratory work, or performance on the mid-semester test. Although they found that the students felt the pre-laboratory exercises were worthwhile, the use of pre-labs did not affect the students’ grades. The lack of significance found in the grade analysis may have resulted from the small sample size of the study (n=63). Similarly, Wyatt (2003) was unable to find any statistical differences in learning outcomes between the students (n=approximately 300) who completed pre-labs and those who did not. During this study, students were expected to complete online simulations or tutorials prior to class. However, Wyatt reported that students who attended lab received an introduction from 62 the instructor, which may have decreased the importance of student preparation and contributed to the lack of a significant difference between student scores. The results found here are more comparable to those found by Johnstone, et al. (1998). These researchers found a significant difference between the mean scores on post-lab assessments following laboratories before which students (n=95) used pre-lab exercises and the labs before which they did not. However, the results from their study may be skewed because the effectiveness of the pre-labs was determined by comparing student scores from different laboratory investigations. The results may have been affected by an interaction between the use of pre-lab exercises and the type of investigation. Although the r-square values in this study were relatively low, the results were statistically significant and showed positive relationships between the student scores. Other studies have drawn similar conclusions on statistical differences with low r-square values. A study from the University of Arkansas at Little Rock (2003) concluded that pre-lab quizzes are an effective tool based on the regression of the students’ (n=29 to 74) post-lab exam scores regressed on their quiz scores. Their analysis showed significant results for ten of thirteen laboratories with relatively low r-square values, ranging from 0.063 to 0.1584. They based their conclusions on the significance of the regression analysis, even though low r-square values were present. This suggests that not only are my conclusions well-founded, but, there may be evidence that pre-lab exercises are more effective than pre-lab quizzes in increasing student performance in the laboratory. 63 Sources of Variation Although firm conclusions may be drawn from the results already presented, the relatively low r-square values demonstrated that the majority of the variation of student scores was not accounted for by simple regression. Many differences among individuals may greatly affect student performance in the science classroom (Trowbridge, et al., 2000). Research demonstrates that students: 1. have preconceptions about natural phenomena 2. vary in their rate of learning 3. have various levels of motivation 4. have differences in their psychomotor skills 5. hold different attitudes, values, and concepts in regard to science Because the data in the present study was from a large enrollment general education introductory course taken by students from any major or year, there was high variation among students in all characteristics. For example, some students, especially the science majors, might have had different and perhaps more accurate preconceptions about the content addressed in lab than did others. This suggests that some students may not have needed as much preparation to perform well on the planning forms and lab reports. Due to different levels of motivation, some students were more likely to seek additional or alternative forms of preparation. For example, some students found the learning resource center or the website useful. These students may have been highly prepared for lab even though their level of preparation was not necessarily reflected by their pre-lab or planning form score. 64 Gender (Milne and Ransome, 1993), culture (Madrazo and Hounshell, 1993), and learning disabilities (Roberts and Bazler, 1993) are all factors that affect student differences in learning and performance. Such student differences are expected to increase the variability in student scores in a large indiscriminate sample, like the one used in this study. One strategy that has been suggested to help students engage in scientific investigation, regardless of their individual differences, is the use of cooperative groups. Groups allow for individual differences while providing students with equal opportunity for student involvement with science equipment and materials (Trowbridge, et al., 2000). In support of such research, the effect of student collaboration can be inferred from my study. In all of the models, the relationships between an individual’s pre-lab and planning form score exhibited the highest coefficients of determination. Models with lab report and pre-lab or planning form scores had lower r-square values. Lab reports resulted from group efforts; therefore, the decrease in the r-square values provides indirect evidence that group collaboration affected student scores. Perhaps, individuals participating in a group did not necessarily need to perform well on the pre-lab or planning form exercises to earn a high score on the lab report. At the beginning of the laboratory, student groups discuss the lab concepts, originate a group hypothesis, and design their experiment. Throughout the lab, students must collaborate to successfully complete the investigation and compose the lab report. Russell and French (2001) found that students in these labs spent more time on task and had higher levels of active participation than students in more traditional, or “cookbook”, laboratories. Such active 65 involvement may be a result of the expectation of equal participation among group members, regardless of individual preparation. The benefits of collaboration were also reflected by the student responses on the survey given at the end of the semester. Most students reported that they felt that their group members were well prepared for lab and that they were able to collaborate well. Most also agreed that when they did not understand a lab procedure their group members explained it. However, most did not agree with the statement inferring that they did not need to prepare individually because their group members did the lab procedures. This statement contradicts a common hypothesis that a group will perform well because one student essentially “carries” the group. The data from this research suggest that in these laboratories, although they prepare individually, the students collaborate their efforts to compensate for individual weaknesses. Other research has studied the benefits of group work in the science laboratory. Howard and Boone (1997) reported that students rated working in groups as the most enjoyable aspect of their laboratory course. Because their students were assigned seats alphabetically (similar to our seating arrangements), they concluded the positive response was not a reflection of friends helping each other. Instead, working in groups provides the opportunity for cooperative learning. Travis and Lord (2004) demonstrated that group interaction increased the level of student involvement in the laboratory. They showed that students working in groups were able to recall and apply the information learned in laboratory better than students that did not participate in a group. Both individual differences and the benefits of group interaction are likely sources of the unexplained variation in these models. Given the data set available, it is difficult to 66 draw firm conclusions on the extent of the effect of these factors. However, including additional variables with the students’ scores provided additional insight to factors that affect student performance in the laboratory. ANCOVA Including Lab Investigation Each of the fourteen lab investigations addressed different content and most required students to apply concepts and procedures unique to the investigation. It was suspected that the student grades might differ depending on the lab investigation because some labs might require more preparation than others. However, the inclusion of lab investigation produced nearly the same coefficients of determination as the general regression models, showing that including lab investigation in the ANCOVA analyses was not useful in reducing the unexplained variance in the regression models. It appears that it was equally important for students to prepare for lab, regardless of the type of investigation being conducted. One possible explanation for the consistency in grades among investigations lies in the course expectations. In both the lab and lecture components of this course, students developed their research skills, including formulating hypotheses, designing experiments, and interpreting results. These skills were required to complete the laboratory assignments. The planning form assignment consisted of a series of questions, most of which were not specific to the lab investigation. Students were expected to write their own hypotheses, outline their procedures, and make predictions for every lab investigation. Of the possible score of ten for a planning form, eight of the points were from these questions. A copy of an example planning form can be found in the appendix (Appendix A). Perhaps students performed consistently on the planning forms regardless 67 of the investigation because they became familiar with the assignment. According to responses on the student survey, most of our students felt confident in their ability to develop a hypothesis and design an experiment. Thus, most students agreed that they could meet most of the requirements on the planning forms used in this course. Similarly, the format and expectations for the lab report were identical every week. Students were expected to include the same type of information in their lab reports, including detailed introduction, methods, results, and discussion sections. A copy of an example grading scheme for the lab report can be found in the appendix (Appendix B). Therefore, it is likely that the student’s scores on planning forms and lab reports did not vary much with the lab investigation because these assignments required the students to apply the same skills and address the same questions during every investigation. Although applying the lab investigation did not improve the covariate model, there were some differences in the relationships between students’ scores depending on the investigation. For example, the regression model of planning form on pre-lab scores was not significant for the final investigation while there was a significant relationship for all other thirteen investigations (p<0.05) (Table IV). The lack of a significant slope may be because this was the last lab investigation and either the students were all performing well regardless of preparation or, perhaps, there were differences in teaching assistant grading standards. From these analyses, I conclude that although including the variable of investigation did not reduce the amount of variation in student scores, it may still be a useful tool to explore student performance in lab and warrants further investigation. 68 ANCOVA Including Section This data set included scores of students separated into thirty four laboratory sections. The regression and ANCOVA analyses demonstrated that including the section variable was very useful in reducing the amount of the unaccounted for variation of these models (pre-lab and planning form, pre-lab and lab report, planning form and lab report), as indicated by the increase in r-square values. In some sections of students, the relationships between scores were highly correlated while there were no apparent relationships in other sections. There are several explanations for why student grades differed by section. The variable of section was a unique combination of the instructor (both lab and lecture), the meeting time of the laboratory, and the students enrolled. The effect of teaching assistant as a classification variable is addressed in the following section of this study. It is possible that the lecture section was a factor on student grades in the laboratory. In each of the lectures (these students were enrolled in one of four sections), instructors used certain scenario software to cover the same material so that the students were equally prepared for the common exams. However, differences still existed among the instructors’ teaching styles, depth of content coverage, and pace. Perhaps students with a particular lecture instructor were able to perform higher on the planning forms or lab reports regardless of their participation on pre-class activities because their instructor covered the content information to a greater extent in their lecture. Some lecture sections may have covered relevant content before some students attended lab and not others because of differences in the day and time of their section. 69 The day of the lab section may also have influenced student grades, either in association with the lecture section or as an independent variable. Perhaps students in lab sections at the end of the week performed well without preparation because their peers enrolled in earlier labs informed the students of later labs about the procedures or content that they would address. Perhaps students enrolled in labs earlier in the week or day were more responsible and more motivated students who were more likely to perform well on assignments. Perhaps evening labs had students who were less dedicated to the course than those willing to enroll in an eight-thirty morning lab, or morning lab students did not perform as well compared to afternoon labs because the students were tired and did not fully engage in the investigation. Sampling may also have contributed to the effect of section on student grades. There were a total of 757 students and 206 groups included in the analyses; however, this number was greatly reduced when considering only the students from any given section. Each section included a maximum of 24 students and a maximum of six groups. This probably resulted in a random distribution of individual student differences across the sections. It is possible that some sections contained more science majors, or more upperclass students, or more dedicated and highly motivated students, etc. Thus, students in certain sections may not have needed to prepare as much to perform well on lab assignments. This would not be a systematic effect (e.g., such as lecture teaching style), but the effect of uneven samples from the larger population. Although other factors may have contributed, the significance of the section variable was likely attributed to student differences across the sections. 70 ANCOVA Including Teaching Assistant During the spring semester of 2004, students had one of seventeen teaching assistants instructing their laboratory section. When I included teaching assistant in an ANCOVA model, it increased the amount of variance accounted for compared to the general regression models. Thus, the teaching assistant model was better able to predict the planning form score based on the pre-lab score. It also suggests that grades were highly influenced by teaching assistant. It is interesting to note the variability of the relationships between students’ scores depending on the teaching assistant. To illustrate, the coefficient of determination of the pre-lab to planning form model was 0.4296 for teaching assistant number eight but was only 0.0798 for teaching assistant number six (Table X). Several explanations for such variation among instructors exist. First, it is possible that some teaching assistants had students who were highly motivated and performed well on assignments. This idea of the random distribution of students and their abilities by teaching assistant is comparable to the explanation for the variation of student grades according to section. With teaching assistant, however, it is less likely that random distribution was a major influence. Each teaching assistant instructed students from two arbitrarily assigned sections. Also, with twice the amount of sample data per teaching assistant, it is less likely that a random distribution of students had a large effect on these analyses. Moreover, although the coefficients of determination of the models including teaching assistant were higher than those of the general models, the relationships were not as strong as those including the section variable. This suggests that even though it is possible that the relationships 71 between students’ scores were affected by chance sampling with the section variable, it is less likely to have been a factor with the models including the teaching assistants. Assuming relative equality of students distributed among the teaching assistants, the instructors had a large influence on student performance in these laboratories. Such influence could have been a result of one of two factors: the teaching assistant’s method of instruction or standard of grading. All teaching assistants participated in an introduction to the course at the beginning of the semester and attended weekly meetings to explore any issues with instruction. At each meeting, the teaching assistants discussed the nature of the investigation and expectations of student completion and performance on the assignments. Teaching assistants, especially those unfamiliar with inquiry-based learning, were highly encouraged to observe experienced lab instructors prior to teaching their own sections. Also, all teaching assistants were provided a “TA survival guide” that detailed how to teach inquiry-based labs, how to evaluate assignments, and what to expect during each investigation. The teaching assistants were expected to instruct and grade in a very similar manner. Unfortunately, it is likely that some teaching assistants did not implement inquirybased instruction as directed because they either did not understand or did not agree with this instructional style in the laboratory. Inquiry-based labs include open-ended scientific investigations that require students to observe, form hypotheses, test, and evaluate (Division of Undergraduate Science, Engineering, and Mathematics Education, 1990). These explorations are student-centered and call for little if any traditional instruction from the teacher. However, if the amount of direct instruction is increased, it may decrease the level of inquiry and subsequently devalue the preparation activities. As 72 emphasized before, students are unlikely to arrive to class prepared if they feel as though the instructor will provide them with all of the information they require to complete the laboratory. Research has demonstrated that instruction from a teaching assistant has a large impact on student success in the laboratory. Kurdziel (2003) described many of the issues with graduate teaching assistants (GTAs). She reported that GTAs had either limited or negative prior experience with inquiry labs. In her study, she found that when the GTAs were observed in their classrooms, they had restructured the lab and did not properly implement inquiry-based instruction. Instead, these lab instructors gave explicit instructions about what the students needed to do, how they needed to analyze their data, and what results they should find. Glasson and McKenzie (1997) concluded that laboratory teachers may have difficulty with the shift from teacher-centered to learnercentered instruction. They found that a teaching assistant chosen to pilot the new instructional method grappled with the problem of how much guidance to offer the students. Pratt (2003) researched cooperative learning in the laboratory and concluded that its success depends on the teacher continually circulating the room to guide students; otherwise the group time is unproductive. Other education researchers suggest that constructing truly cooperative groups requires years of teaching experience and many teaching assistants frequently encounter problems facilitating group work (Jensen, et al., 2005). Thus, it is possible that the students’ success in lab was also affected by an interaction between their teaching assistant and their group collaboration. 73 If research such as this consistently found that teaching assistants are challenged by inquiry-based instruction, it is likely that some of the same problems were experienced by the instructors of the laboratories in this study. Unexpectedly, 82% of the biology students strongly agreed or agreed with the statement that their TA explained all the procedures before class. Therefore, I conclude that some teaching assistants were not leading their students to fully engage in an inquiry-based lab, which would have affected their performance on the laboratory assignments. This agrees with French and Russell (2002), who found that teaching assistants with less experience in inquiry-based laboratories were less inclined to use that method in teaching than those with more experience. Even though the biology lab instructors discussed expectations during the weekly meetings and had explicit directions in the TA guide, it was likely that the grading standards were not identical among all of the teaching assistants. Some probably demanded higher performance levels from their students than others, regardless of the predetermined expectations. To illustrate, the table and graph of pre-lab and planning form scores shows that teaching assistant number ten had a slope significantly different than zero (p<0.0001) but also had scores consistently lower than any other teaching assistant. This suggests that although this teaching assistant had student scores that demonstrated a strong relationship with the increase of a pre-lab score predicting the increase of the planning form score, he/she may have been grading strictly relative to the other teaching assistants. On the other hand, teaching assistant number three had consistently high student scores but the slope of the line was not significantly different than zero (p=0.2741) (Table X, Figure 10). This teaching assistant may have been 74 grading too leniently and those students did not have to participate in the pre-lab in order to earn a high score on the planning form. Discrepancies in teaching assistant grading standards have also been expressed by students, such as this statement on the survey: “Some TA grading was not consistent; some TAs were extremely lenient in comparison to others”. Also, the majority of these students (70%) reported that they regularly received full credit on their planning forms. It is difficult to rely on student opinions on the appropriateness of teaching assistant grading considering how often students taught by many different teaching assistants are convinced that they have the harshest teacher. However, it may have been more than student perception that teaching assistant expectations were not equal. Analyses of the Student Survey The student responses corroborate the interpretations of the grade analyses. The majority of the students reported that they regularly completed the pre-labs and planning forms and most students felt that they were prepared for lab each week. This suggests that the students found the pre-class assignments valuable, which is a noteworthy outcome in itself. This is consistent with other studies (Barnes and Thornton, 1998, Johnstone, et al., 1998, Kirk and Layman, 1996, Wyatt, 2003). I also found that most students enjoyed working in groups and agreed that their group members explained lab procedures if they did not understand them. Other studies have also found that students enjoy working in groups in the laboratory (Pratt, 2003, Travis and Lord, 2004). This supports the idea that there were lower coefficients of determination in the models predicting lab report scores because of student collaboration. One student eloquently wrote that he/she enjoyed this aspect of the course because “it 75 (working in groups) helped when there were many minds over just one”. The results also support the proposed variability in teaching assistant instruction. Nearly half the students reported that they strongly agreed that their TA explained all the procedures before class. Perhaps the most interesting aspect of the student survey was the variability in the open-ended responses. When students were asked to comment on their favorite and least favorite aspects of the course, many reflected on the same topics but evaluated them with opposing views. For example, with respect to group work, one student responded that he/she liked this aspect the most stating “…we were all cooperative and helped each other”. Another student reported a desire to change this aspect of the course because he/she “…like[s] individual effort”. One student commented that his/her favorite aspect of the course was “all of the TAs” while another said that the “TAs in lab need to be more helpful”. These student responses demonstrated that although this course was designed to consistently provide equal learning opportunities all students, they often had very different experiences. The wide range of student perceptions may be a reflection of individual differences, which likely increased the unexplained variation of student grades in the regression models. Conclusions Many factors affect student performance in the laboratory. It is important for students to prepare prior to attending an inquiry-based lab and the use of pre-labs and planning form assignments can be effective. These pre-class assignments can influence the students’ grades and the students themselves found the pre-class assignments valuable. However, student performance in the laboratory is connected to variables other than their participation on these preliminary exercises. Although lab investigation may 76 not be a factor, student performance is highly affected by the lab section and teaching assistant. The section effects may be a result of a random distribution of student differences, the lecture section, their instructor (either in lecture or laboratory), or the meeting day and time of the laboratory. The differences resulting from the inclusion of teaching assistant are likely attributable to differences in instruction style or grading standard. Also, the results of these analyses also show that student collaboration in groups is probably an important aspect of student performance in laboratory. Other factors that likely affect student grades are individual skills and science abilities, personal attributes such as gender and classification, and student participation and motivation. Although many variables affect student performance, quantitative and qualitative methods used in this study demonstrate that pre-class activities are valuable tools for preparation in the laboratory. Recommendations for Future Research More research on pre-class exercises and student performance could be completed in several areas. The course used in this study did not allow for any comparison with a control group. It may be beneficial to design a study in which there are some students who complete pre-labs or planning forms and others who do not. This may provide more definitive data on how effective these pre-class activities are in helping students to prepare for and then succeed in the laboratory. The qualitative portion of this study was limited to a survey given to students at the end of the course. It would be interesting to evaluate student perceptions at different times during the semester. Perhaps students value the pre-lab or planning form 77 assignments differently at the beginning of their lab experience as compared to the end when they are more accustomed to the investigative requirements. Differences in students’ scores by major, year of study, gender, ethnicity, and other personal factors could be explored. It may be helpful to collect these data to reduce the variation by using each quality as a classification variable. Analyzing the grades of a specifically chosen group of students may provide additional insight into factors affecting student preparation and performance in the laboratory. The effect of the lab instructor could also be explored. This research demonstrated that student grades differ depending on the teaching assistant of the lab section. As suggested, this may be a result of instructional style. To test this hypothesis, lab instructors could be observed and categorized by how effectively they implement an inquiry-based laboratory. Multiple comparison procedures could be performed to determine if there is a significant difference in student’s grades between teaching assistants who more fully apply inquiry instruction and those who implement more direct instruction. If the teaching assistant allows for student-centered investigations during the laboratory, then student preparation should significantly correlate with student success. In contrast, an increase in the amount of direct instruction from the teaching assistant may result in a decline in the importance of student preparation. It may also be useful to explore student performance in the laboratory based on the type of investigation. Although these analyses showed that using the investigation as a classification variable was not useful in reducing the variation in the data, it may be beneficial to perform additional analyses. Multiple comparison procedures could be applied to compare the more open-ended investigations with those that call for more 78 specifically defined procedures. It may also be useful to compare investigations that require the students to know more conceptual background to those that involve more procedural knowledge. This information could help instructors develop more useful preparatory exercises for students in an inquiry-based laboratory. 79 LITERATURE CITED American Association for the Advancement of Science. 1990. The Liberal Art of Science: Agenda for Action. American Association for the Advancement of Science: Washington, D.C. Astrachan, Owen L. November 4, 1999. CPS 06, fall 1999: Setup for Prelab. http://www.cs.duke.edu/courses/cps006/fall99/labs/lab8.html (April 8, 2005). Barnes, Roslyn and Barry Thornton. 1998. Preparing for laboratory work. In Black, B. and Stanley, N. (Eds), Teaching and Learning in Changing Times, 28-32. 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Campus Technology: Online Biology Pre-Labs. http://www.campus-technology.com/article.asp?id=7770 (April 14, 2005). 84 APPENDIX A An example of a planning form (with the pre-lab questions). 85 86 APPENDIX B An example of the lab report grading scheme. 87 APPENDIX C A copy of the survey given to students at the end of the semester. 88 89 VITA Melissa Rose Gentry Candidate for the Degree of Master of Science Thesis: STUDENT SUCCESS IN AN INQUIRY-BASED LABORATORY: THE EFFECT OF PRE-CLASS ACTIVITIES AND STUDENT PREPARATION Major Field: Zoology Biographical: Personal Data: Born in Tulsa, Oklahoma on April 23, 1980 to Thomas and Ruth Willis. Education: Graduated from Union High School in Tulsa, Oklahoma in May of 1998; received Bachelor of Science in Secondary Science Education from Oklahoma State University in May of 2002; completed the requirements for Master of Science in Zoology at Oklahoma State University in July of 2005. Experience: I was employed as a Teaching Assistant for the introductory biology course at Oklahoma State University during the academic years of 2003-2004 and 2004-2005. During this time I also extended my experience in biological science coursework and science education research. Professional Memberships: National Association of Biology Teachers (NABT), National Science Teachers Association (NSTA), Society of College Science Teachers (SCST) Name: Melissa Gentry Date of Degree: July, 2005 Institution: Oklahoma State University Location: Stillwater, Oklahoma Title of Study: STUDENT SUCCESS IN AN INQUIRY-BASED LABORATORY: THE EFFECT OF PRE-CLASS ACTIVITIES AND STUDENT PREPARATION Pages in Study: 89 Candidate for the Degree of Master of Science Major Field: Zoology Scope and Method of Study: Many instructors agree that students need to prepare prior to attending class, especially for laboratory. While some instructors provide pre-class activities to help students prepare, there is little research to support the conclusion that they are effective. This study examined their effectiveness in an introductory biology course that employed the use of pre-class activities for student preparation. The laboratory component of the class was designed to enhance students’ scientific literacy through inquiry. Each week, given background information and a question to investigate, the students designed and conducted an experiment, analyzed their data, and wrote a lab report. To help students prepare for the investigation, students were expected to complete two pre-class assignments, a planning form and a pre-lab. To test the relationships between student preparation and performance, I performed regression analyses of the following models: pre-lab and planning form scores, prelab and lab report scores, planning form and lab report scores. To determine the effects of other possible factors, lab investigation, section of enrollment, and teaching assistant were included in the models. I also analyzed student perceptions concerning the preparation activities and other aspects of the laboratory. Findings and Conclusions: There were statistically significant and positive relationships between student scores in the three models. Students that performed well on pre-labs were more likely to perform well on planning forms and student groups that performed well on pre-labs or planning forms were more likely to perform well on the lab reports. This indicated that student preparation effected performance in lab. However, the relatively low variance accounted for by these models alone showed the presence of other factors affecting student performance. The coefficients of determination of the models increased substantially when section or teaching assistant was included in ANCOVA analyses. This supports the conclusion that sources of variation may be from student differences in skills and abilities or the instructional style and grading standard of the lab instructor. There was also indirect evidence that group collaboration affected student scores in these laboratories. ADVISOR’S APPROVAL: Donald P. French