Spring 2001 REHB 509B Behavior Analysis Research Designs: Group Experimental Designs The syllabus is subject to error correction and minor change in content during the course. Instructor: Anthony J. Cuvo, Ph.D. Rehn 311A acuvo@siu.edu Phone 536-7704; FAX (618) 453-8271 http://www.siu.edu/~rehabbat/Enhanced/faculty.html Syllabus On-line: http://www.siu.edu/~rehabbat/Cuvo/Rhab509b.pdf Time: 12:00-1:15 PM, Tuesday and Thursday Classroom: Rehn 326 COURSE DESCRIPTION & GOALS: The purpose of this course is to provide a foundation in applied research methods pertinent to program evaluation, group experimental design, and related data analysis. After completing the course you should be able to do the following: a) Be a knowledgeable consumer of group design and related statistical analysis literature (i.e., understand and critically evaluate research in journal articles and other research presentations). b) Have intermediate level skill generating group design studies, knowing which data analysis techniques are appropriate, using a computer for basic statistical analyses, and drawing appropriate conclusions. Principal Text (available at local bookstores) Christensen, L. B. (2001). Experimental Methodology (8th ed.). Boston: Allyn & Bacon. Huck, S. W., (2000). Reading statistics and research (3rd ed.). New York: Addison Wesley Longman. REHB 509B Syllabus 2 Additional Required Readings Additional readings are available from the Printing Plant, 606 S. Illinois Avenue. These readings, indicated by asterisks in the syllabus, supplement and are equally important to those in the textbooks. Page through the entire reading packet as soon as you get it and compare it to the syllabus. If you find missing pages or pages that are not legible go to the Printing Plant and ask them to rectify the situation. You are responsible for all assigned readings on the due date. Requirements and Grading 1. There will be 4 tests @ 100 points each on: February 13, March 20, April 12, May 9. Tests will emphasize the material since the previous test; however, the content is cumulative and you should be able to relate earlier concepts to the current material on the tests. Students must remain in the classroom until finished with the test. Take care of any personal needs before coming to the classroom. Total possible: 400 points 2. There are 3 conceptual projects that require you to apply the material in this course. The forms for the first two are available on-line at http://www.siu.edu/~rehabbat/ExpDesignProj.doc. The form in is Microsoft Word format and can be downloaded on disk or to your computer. You will need to use Word or a program that will open Word. The form is the same one used in Rehab. 509A. Although projects 1 and 2 could be on the same general topic (e.g., child abuse, biofeedback, mental retardation), each must be on a different specific topic. Projects should include a new literature review and independent variable. Projects should not be just minor variations of each other. About 90% of the points lost in past years have been due to not following APA style and not answering all components of the questions. Put Projects in instructor's mailbox in Rehn 317 by 4:00 PM on the due date. Note that Rehn 317 will be locked promptly by 4:30 PM. The office also will be closed between 12:00-1:00 PM. There will be a 33% per day reduction in the maximum point total for late assignments, including weekend days. Project due dates and point values: Project 1 (3/5/01) 20 points Project 2 (4/2/01) 25 points Project 3 (4/30/01) 10 points Total possible: 55 points REHB 509B Syllabus 3 3. A 15 minute quiz will be given at the beginning of 22 classes indicated on the syllabus. Each quiz will be worth 10 points. If you come to class while the quiz is being administered, you will have until time expires on the quiz to finish. If you come to class after the quiz has been completed, you will not have the opportunity to take it and you will receive a grade of 0 for that quiz. If you plan to be absent from class, it is your responsibility to arrange to take the scheduled quiz or test in advance of the class you will not attend. Total possible: 220 points Point to letter grade conversion: A = 675-607 points B = 606-540 points C = 539-472 points Lower grades are available on the same proportional scale. If you have earned 90% of the points up to and including the first 18 quizzes, first three tests, and the three projects (i.e., 481 points exactly, no rounding) and made a minimum score (not average) of 9 on each quiz in the last course unit, you will be exempt from taking the final exam and receive an “A” in the course. The quiz points for the final unit are not included in the 90% criterion. • If you are having difficulty with this material, see the professor as soon as possible. • If you wish to drop this course for any reason, the Graduate School has a final date that you can do this. It is your responsibility to drop by the date designated by the Graduate School. • A grade of Incomplete will be given only under the conditions specified in the Graduate School Catalog. The reading list includes a number of journal articles that present experimental research. These articles serve as models for the integration of conceptual issues, research questions, measurement procedures, experimental design, data analysis, and inferences from the data to past research and conceptual issues. You should read these articles and try to understand the integration of the various components of the research process; however, an article has been assigned for a particular class because it illustrates the topic for that class. Focus, in particular, on the aspect of the article that is related to the topic for that class. REHB 509B Syllabus 4 You will have three statistical projects to do in this course using a computer and software of your choice. It is recommended that you identify the computer and software that you will use and gain familiarity with both before you start your first project. The readings and exercises from the Internet are no different from other assigned readings with respect to their importance and availability for material for quizzes and tests. It is recommended that you take your readings to class, especially the ones for that day. A number of computer data analysis examples have been included in your reading packet. They present a research question, design, computer data analysis, and interpretation. Various statistical packages have been used for these examples. Try to understand the research and data analysis, and don’t get bogged down in the mechanics of how to use the software. You should try to understand the printouts and interpretation of results. Try to do the readings in the sequence indicated on the syllabus. REHB 509B Syllabus 5 ***January 16, 2001 Introduction to course Video: Facilitated Communication ***January 18-23, 2001 (Science & Theory) Readings: 1/18/01 "Much like the law of gravity, the laws of learning are always in effect. Thus, the question is not whether to use the laws of learning, but rather how to use them effectively." From "Learning Principles" (Spreat & Spreat) The above quote is related to the goal of science, to discover the orderliness or lawfulness in nature. Those lawful relations about human behavior always have existed, and they are there waiting for us to discover them. We discover them using scientific methods, and that discovery can lead to useful applications in human services. This course focuses on the role of certain aspects of scientific methodology as a tool for understanding variables that relate to human services. These initial readings are a varied collection that have a common theme- the big picture pertaining to research and program evaluation. They address philosophical issues, definition and characteristics of science, research questions, and conceptual issues. They address the larger issues that surround the more focused tactics of research methodology. Christensen Chap. 1 * Shermer, M. (1992). A skeptical manifesto. Skeptic, 1, 15-21. (This article advocates a basic approach, a “mind-set” as some might say, to examine claims about causal events in the universe. Do you believe everything that people tell you? How do you decide what to believe? What is your criterion for truth?) * Cuvo, A.J. Rational Skepticism and Research Methodology * Green, G. (1996). Evaluating claims about treatments for autism. In C. Maurice, G. Green. & S. C. Luce. (Eds.). Behavioral intervention for young children with autism (pp. 15-28). Austin: Pro-Ed. REHB 509B Syllabus 6 1/23/01 Christensen, Chaps. 3 & 4 * Cuvo, A. J. How to Ask Research Questions or Words Mean Something * Exploring psychology scientifically-Asking testable questions http://gateway1.gmcc.ab.ca/~digdonn/psych104/think.htm (Download from Internet. Test yourself with this exercise.) * Riggin, L.J.C. (1990). Linking program theory and social science research. In L. Bickman (Ed.), New directions for program evaluation: Advances in program theory, no. 47 (pp. 109-120). San-Francisco: Jossey-Bass. (This article makes a point similar to that made by Cuvo above. It shows not only that human service programs should have a theory on which the program delivered to clients is based, but also the program theory should be evaluated in light of the manner in which the program actually is delivered. Is the program as conceptualized on paper, congruent with the program in operation? Does the program theory have to be revised to reflect reality?) QUIZ 1 1/23 only, based on readings for both dates. No quiz on 1/18 ***January 25-30, 2001 (Variables Used in Experimentation; Measurement Principles and Applications) Readings: 1/25/01 You might want to read pp. 101-105 from Meltzoff and then the pages from Christensen on the independent variable first, and then the remaining of the Meltzoff and Christensen chapters on the dependent variable. Christensen Chap. 6 * Cuvo, A. J. Independent Variables and Conceptual Models *Meltzoff, J. (1998). Chap. 7 Criteria and criteria measures. In Critical Thinking About Research. APA: Washington. QUIZ 2 REHB 509B Syllabus 7 1/30/01 * Cuvo, A. J. Translating Conceptual Variables to Measurable Variables * Cuvo, A. J. Documenting Client Progress Huck Chap. 4 * Anastasi, A. & Urbina, S. (1997). Psychological testing (7th ed.).Upper Saddle River, NJ: Prentice Hall Chaps. 4-5. (You should understand each type of reliability and validity. What is its purpose? How does one establish the specific type of reliability and validity procedurally? Which ones would you use in a particular situation?) QUIZ 3 ***February 1, 2001 (Pseudo- or Pre-Experimental Designs) Readings: * HCB (1st. Ed.), Chap. 11 (focus on experimental design and not statistical analysis) Christensen, pp.232-238. * Holden, P. & Neff J. A. (2000). Intensive outpatient treatment of persons with mental retardation and psychiatric disorder: A preliminary study. Mental Retardation, 38, 27-32. (Focus on design and not data analysis. What pre-experimental design was used? What research questions can it and can it not answer?) QUIZ 4 ***February 6, 2001 (Internal-Validity) Readings: Christensen, Chap.7 Re-read the HCB Chap. 11 from last class and focus on internal validity of designs. * Cuvo, A. J. Threats to Internal Validity in Experimental Research * Cuvo, A. J. A Note on Testing as a Threat to Internal Validity and Pretest and Posttest Sensitization as Threats to External Validity. (Read first paragraph) REHB 509B Syllabus 8 * Kruger, J., Savitsky, K., & Gilovich, T. (1999). Superstition and the regression effect. Skeptical Inquirer, 23(2), 24-29. QUIZ 5 ***February 8, 2001 (Quasi-Experimental Designs) Readings: * HCB (1st. Ed.), Chap. 14 (up to p.323, focus on experimental design and not statistical analysis) Christensen, Chap. 10 The following articles involve quasi-experimental designs. Understand which specific design was employed, what research question(s) it can and cannot answer, and how well this design controls for threats to internal validity. * Slate, J. R., & Jones, C. H. (1989). Can teaching of the WISC-R be improved? Quasi-experimental exploration. Professional Psychology: Research and Practice, 20, 408-410. * Schnelle, J.F. & Lee, J.F. (1974). A Quasi-experimental retrospective evaluation of a prison policy change. JABA, 7, 483-496. * Wilderman, R. (1981). Psychotherapy in a community mental health facility. Evaluation and the Health Professions, 4,189-205. QUIZ 6 ***February 13, 2001 TEST 1 ***February 15, 2001 (True Experimental Designs & External Validity) Readings: Note: True experimental designs control for most threats to internal validity by random assignment of subjects to conditions, and do not require an individual analysis of the plausibility of each threat as was the case for pre-and quasi- experimental designs. REHB 509B Syllabus 9 * HCB (1st ed.), Chap. 12 (Focus on design issues and not data analysis. The use of gain scores and the independent t test are not a recommended approach to statistical analysis for the pretest-posttest control group design as suggested in this chapter. When you use a gain score, you lose the reliability of the underlying measurement that was the basis for calculating the gain score. The pretestposttest control group design is also called a Two Factor Mixed Design with One Repeated Measure. You will learn about an ANOVA for this design in a future class). * Cuvo, A. J. A Note on Testing as a Threat to Internal Validity and Pretest and Posttest Sensitization as Threats to External Validity. (Read all. See previous class) Christensen Chaps. 8 (Except sections on counterbalancing) & 14 * Designing research studies in psychology http://gateway1.gmcc.ab.ca/~digdonn/psych104/var.htm (Download from Internet) * Class Exercise-matching and randomization-Take these to class QUIZ 7 ***February 20-27, 2001 (Basic Statistical Issues) Readings: 2/20/01 Christensen, Chap.12 Huck, Chap. 2 * Normal Curve QUIZ 8 2/22/01 Huck, Chaps. 5-6 * Cuvo, A. J. & Hewes, R. L. Population & Sampling QUIZ 9 2/27/01 Huck, Chaps. 7-9 REHB 509B Syllabus 10 QUIZ 10 REHB 509B Syllabus 11 ***March 1, 2001 (T-Tests) Readings: You need to understand the logic of the t-test as represented in the formula. What does the numerator mean? What does the denominator mean? What does the t test do and how does it do it? What does the calculated value of t really mean? Re-read comments above about not using t test for pretest-posttest control group design under introduction to True Experimental Design. Huck, Chap.11 (Skip sections on “Inferences Concerning a Single Mean”,p.285290. Christensen, pp. 326-335. * Independent t Test Example (This analysis was done on the Excel software and serves as a model for Project 1. This provides you an applied research example where the independent t test was used. ) * Dependent t Test Example (This analysis was done on the Excel software and serves as a model for Project 1. This provides you an applied research example where the dependent t test was used.) * Cuvo, A. J. & Hewes, R. L. Using t Tables (Includes “Critical Value of ‘Student’s’ t statistic”) * Holden, P. & Neff, J. A. (2000). Intensive outpatient treatment of persons with mental retardation and psychiatric disorder: A preliminary study. Mental Retardation, 38, 27-32. (See pseudo-experimental design class. Focus on data analysis and interpretation) * Cuvo, A. J. Effect of Within Groups Variability on the t Test QUIZ 11 ***March 5, 2001 Applied Exercise 1 - Conduct a literature review, derive a research question, and design an experiment whose data would be analyzed by either an independent or dependent t test. Generate hypothetical data for this exercise. Use the Experimental Research Design Form to do this and attach a table of the raw data for each experimental condition, and a computer printout of results. Include in your data analysis the M and S.D. for each experimental condition. Do statistical analysis using any computer and software of your choice. State at the top of your report the name of the computer and software. The t test examples on the reading list provide models for this project. REHB 509B Syllabus 12 ***March 6-8, 2001 (One Way ANOVA; Post hocs.) Readings: 3/6/01 Huck, Chap. 12 * Cuvo, A. J. The logic of ANOVA (You need to know the logic of the ANOVA as represented in the formula and discussed in this paper. How are the components of ANOVA calculated?) * Cuvo, A. J. & Hewes, R. L. Using F tables (Includes “Percent Points in the F Distribution”). * Read the relevant section of Cuvo, A. J. Relationship Between Experimental Design and ANOVA (See Mixed Factorial Design Class below) QUIZ 12 3/8/01 Huck, Chap. 13 * The Tukey test and table (Note: A post-hoc test, such as the Tukey test, will be needed for any significant F that is based on 3 or more means. The n per group is based on the number of subjects that went into the calculation of the mean per group.) * Kregel, J., Wehman, P., & Banks, P. D. (1989). The effects of consumer characteristics and type of employment model on individual outcomes in supported employment. JABA, 22, 407-415. (Focus on ANOVA and post-hoc analyses and not chi-square analyses) * ANOVA For One factor CRD (For this and subsequent computer analyses, focus on the example of applied research and interpretation of results rather than the mechanics of the computer data analysis.) QUIZ 13 REHB 509B Syllabus 13 ***March 20, 2001 TEST 2 ***March 22-27, 2001 (Between Subjects & Randomized Blocks Designs) Readings: Huck, Chap. 14 * HCB (1st ed.) pp. 281-284. Christensen, pp. 246-252, 346-357. Note: If an ANOVA has both significant main effects and interactions, you will have to compute more than one Tukey test because the q value and the n per group, which is in the denominator under the square root, will change. The n per group is based on the number of subjects that went into the calculation of each mean for rows, columns, or cells. The Tukey critical difference will not be the same for main effects and interactions when they differ with respect to number of means and n per group. Assume a 2 Factor Completely Randomized Design with 2 levels on Factor A and 3 levels on Factor B. Further assume that there are 10 subjects per cell or a total of 60 subjects (2X3X10=60). If the F for Factor A is significant, no post-hoc test would be needed because there are only 2 levels and 2 means involved. If the F for Factor B is significant, you will have to calculate a Tukey based on a q involving the 3 means for the three levels of the independent variable, and an n of 20 subjects per row group. In this case, the group is one entire row or column that contributes to the mean. For the interaction, there are 6 means for the 6 cells (2x3) in the design and an n of 10 per group. The MS within group or error will be the same for all Tukey tests based on the same ANOVA because there is only one MS error in the ANOVA. * Read about the relevant designs on Cuvo, A. J., Relationship Between Experimental Design and ANOVA (See Mixed Factorial Design Class) * Kennel, R. G. & Agresti, A. A.. (1995). Effects of gender and age on psychologists’ reporting of child sexual abuse. Professional Psychology: Research and Practice, 26, 612-615. (Explain the experimental design. Focus on ANOVA and Post-hoc analyses and not chi-square analyses) * Bordieri, J. E., Comninel, M. E., & Drehmer, D. E. (1989). Client attributions for disability: Perceived accuracy, adjustment, and coping. Rehabilitation Psychology, 34, 271-278. (Explain the experimental design.) REHB 509B Syllabus 14 * ANOVA for a 2 factor CRD (This is a general model for your next project. This example has two IVs with only 2 levels on each IV. Your project, in contrast, has 2 IVs with 3 levels on each IV. It might be a good idea to run this analysis with the data in your handout as a practice for your next project. You will have to generalize from this example to entering one more level on the 2 IVs). * ANOVA for a Randomized Block Design (Treatment by Levels) * Cuvo, A. J. Possible Outcomes for a Two factor Experiment (Look at this handout to see all possible outcomes from a 2 factor experiment. You should be able to explain each outcome and draw the appropriate figure.) Huck, Chap.15 * ANOVA for a 3 factor CRD QUIZ 14 3/27 only, based on readings for both dates. No quiz on 3/22. April 2, 2001 Applied Exercise 2 - Conduct a literature review, derive research questions, and design an experiment with two between subjects independent variables with two levels on each variable. Generate hypothetical data for this exercise, and do so in a manner that results in at least one significant main effect and an interaction. This means that you have to understand the concept of how a main effect and interaction are created. Use the Experimental Research Design Form to do this, and attach a table of the raw data for each experimental condition, and a computer printout of your results. Do statistical analysis using a computer and software of your choice. Name them at the top of your report. Your report should include the M and S.D. for each condition, the complete ANOVA table, a graph of the interaction, post-hoc tests as needed (do by hand if computer program does not do this and show step-by-step computations). For your report, note that an interpretation of results is a description of which conditions are and are not significantly different from each other, and not just a statement of the statistics. Remember that the interaction qualifies the interpretation of the main effect. The ANOVA for a 2 Factor CRD example on the reading list provides a model for this project. You will have to generalize to three levels on the independent variables. EXCEL will not do this analysis. You could use Statview available in the College of Education Computer Lab. ***March 29, 2001 (Repeated Measures Factorial Designs) Readings: Huck, Chap. 16 Christensen, pp. 252-255. REHB 509B Syllabus 15 Cuvo, A. J. A Note on Test Scores as a Dependent Variable and Test Trials as an Independent Variable. * Read the relevant section of Cuvo, A. J. Relationship Between Experimental Design and ANOVA (See Mixed Factorial Design Class below) Christensen, Chap. 8 (sections on counterbalancing only. See True Experimental Design class) * Cuvo, A. J. Crossover or Changeover Design * Fujiki, M. & Brinton, B. (1993). Comprehension monitoring skills of adults with mental retardation. Research in Developmental Disabilities, 14, 409-421. Re-read Slate & Jones (see quasi-experimental design class) and focus on data analysis QUIZ 15 ***April 3, 2001 (Mixed Factorial Designs) Readings: Huck Chap. 17 Christensen, pp. 255-259. * Finlayson, L. M., & Koocher, G. P. (1991). Professional judgment and Child abuse reporting in sexual abuse cases. Professional Psychology: Research and Practice, 22, 464-472. (Explain the experimental design and data analysis.) * Keefe, F. J., Surwit, R. S., & Pilon, R. N. (1980). Biofeedback, autogenic training, and progressive relaxation in the treatment of Raynaud's disease: A comparative study. JABA, 13, 3-11. (Explain the experimental design and data analysis.) * ANOVA for a 2 Factor Mixed Design * Cuvo, A. J. Factors That Affect F * Cuvo, A. J. Relationship Between Experimental Design and ANOVA QUIZ 16 REHB 509B Syllabus 16 ***April 5, 2001 (ANCOVA) Note: ANCOVA is a statistical test and not an experimental design. It can be used instead of an ANOVA in any of the experimental designs presented above. ANCOVA provides statistical control rather than control using experimental design tactics. You should understand the situations for which ANCOVA is the more appropriate analysis than ANOVA, and the logic of how it works. Readings: Huck, Chap. 18 * Kottke, J. L., Mellor, S., Schmidt, A. C. (1987).Effects of information on attitudes toward and interpersonal acceptance of persons who are deaf. Rehabilitation Psychology, 32, 239-243. * ANCOVA for Pretest Posttest Control Group Design QUIZ 17 ***April 10, 2001 (MANOVA & MANCOVA) Note: MANOVA and MANCOVA are used to analyze data from multivariate experiments (i.e., those with more than one dependent variable). You should understand the rationale for using MANOVA and MANCOVA, instead of ANOVA, how these multivariate tests generally operate, and how to interpret results from these analyses. Readings: * HCB (1st ed.) Chap. 9 Multivariate Analogs to the T Test , ANOVA, & ANCOVA Reexamine Huck pp. 203-208, the data analysis in the Wilderman article, discussion of Bonferroni inequality test in Finlayson & Koocher (p. 468). * Church, P., Forehand, R., Brown, C., & Holmes, T. (1990). Prevention of drug abuse: Examination of the effectiveness of a program with elementary school Children. Behavior Therapy, 21, 339-347. * Cuvo, A. J. Data Analysis Discriminations-Section A QUIZ 18 ***April 12, 2001 REHB 509B Syllabus 17 TEST 3 REHB 509B Syllabus 18 ***April 17-29, 2001 (Nonparametric Statistics) Readings: 4/17/01 Note: Nonparametric statistics is a class of statistics used to analyze data that do not meet the assumptions of parametric statistics. Previous chapters have stated assumptions for parametric tests, and you should understand these assumptions. Furthermore, you should understand conditions that violate these assumptions, and use the Nonparametric Statistic Tests chart to identify an appropriate statistic for analyzing the data. A primary learning objective for you is to use the “Nonparametric Statistic Tests” chart to identify an appropriate nonparametric statistic for a research situation. Use the past test and quiz questions to practice. *Siegel, S. & Castellan, N. J., Jr. (1988). Nonparametric Statistics (2nd. ed.) (pp. 19-36, Nonparametric Statistics Tests table). New York: McGraw-Hill. The objective for the table at the end of the chapter is for you to learn to make the necessary discriminations about a research context (i.e., level of measurement, number of cases, whether they are related or independent) to identify the nonparametric tests that would be appropriate for the situation. At that point, you would have to read in greater detail about how to perform the tests. This table would be made available on the last test if there are related questions. Huck, Chap. 20 * Amick-McMullan, A., Kilpatrick, D. G., & Resnick, H. S. (1991). Homicide as a risk factor for PTSD among surviving family members. Behavior-Modification, 15, 545559. Re-read Kennel & Agresti (1995) and Kregel et al. (1989) above and focus on how statistical analyses change to fit the research questions asked and data characteristics. * Complex Chi Square and the Contingency Coefficient * Chi Square as a Test of Independence QUIZ 19 4/19/01 Huck, Chap. 21 REHB 509B Syllabus 19 * Callahan, W. P. (1983) The effectiveness of instructional programming on the reduction of dental disease in mentally retarded individuals. Mental Retardation, 21, 260-262. * Mann Whitney U Test * Wilcoxon Matched Pair Signed Rank Test * Friedman Two Way ANOVA by Ranks * Kruskall-Wallis One Way ANOVA by Ranks * Review Data Analysis Discriminations-Section A QUIZ 20 ***April 24-26, 2001 (Bivariate Correlation) Note: The data analysis techniques at this point in the course take a different turn. The correlational statistics are used to answer research questions pertaining to the relationship or degree of association between variables, and how well several variables taken together can predict one or more criterion variables. This type of research question is in contrast to previous research questions pertaining to the significance of difference between population parameters. Correlational analyses can make use of measured variables (i.e., Ss are simply evaluated and scored on various dependent measures) and not manipulated variables in the context of experimental design as you saw previously. Although there are ostensible differences between tests of significance of difference and correlational procedures, they are fundamentally the same. For all the bivariate and multivariate analyses, the goal should be for you to have an understanding of what these tests show in a practical sense. You need not remember formulas here. Readings: Huck, Chaps. 3 & 10 Correlational vs. experimental studies http://gateway1.gmcc.ab.ca/~digdonn/psych104/cor.htm (Download from Internet) * Appropriate Correlational Techniques for Different forms of Variables (The key to understanding correlational techniques is to determine how many variables there are, their level of measurement, and whether they are predictor or criterion variables. A primary learning objective for you is to use the page titled Appropriate Correlational Techniques for Different forms of Variables to identify an appropriate correlational statistic for a research situation. Use the past test and quiz questions to practice. If REHB 509B Syllabus 20 there are questions relevant to this on the last exam, this page will be made available to you.) * Range of values of r (You should understand the shape and slopes for the various correlations) * Critical Values of Pearson r (Note: n’ refers to pairs of scores being correlated. This table is used similar to that for the t test. You enter it with the appropriate df and alpha level and find the critical value of r.) * Hodapp, R. M., Evans, D. W., & Ward, B. A. (1989).Communicative interaction between teachers and children with severe handicaps. Mental Retardation, 27, 388395. * Pearson Product-Moment Correlation * Spearman Rank-Order Correlation * Point Biserial Correlation Coefficient Read the following news announcement and infer how the study was conducted. What can be said about a cause and effect relationship between drinking coffee and getting colorectal cancer? Coffee may cut colon cancer risk (Reuters) - Coffee drinking has been linked to a lower risk of colorectal cancer in a majority of recent studies, according to a review published in the current issue of the American Journal of Epidemiology. Dr. Edward Giovannucci of the Harvard School of Public Health, Boston, Massachusetts, writes that "a lower risk of colorectal cancer is associated with higher levels of coffee consumption." QUIZ 21 4/26 only, based on readings for both dates. No quiz on 4/24 ***April 30, 2001 Applied Exercise 3 - Write a research question that asks about the degree of relationship between two plausible variables relevant to human services. Name the variables that you are measuring and state their level of measurement. Generate 20 hypothetical scores on each variable and do the appropriate statistical analysis by computer. In addition to the information stated above, include in your report the name of the computer software, raw data, null and alternative hypotheses, name of statistical test, appropriately labeled scatterplot of data which could be done by hand or computer, statistical results including critical value of the statistic, calculated value of the statistic, percentage of variance explained, and interpretation of results including decision REHB 509B Syllabus 21 regarding Ho. The interpretation should describe the specific relationship between the variables (e.g., as people get older, they tend to get heavier). If any of the information requested is on printouts, please put it in your report. Note that this project is done on your own paper and not the form that you used for the previous two projects. Be sure your report includes all the items cited above. The Pearson Product Moment Correlation example on the reading list provides a model for this project. *** May 1-3, 2001 (Multiple Regression Analysis) Readings: * HCB (1st ed.) Chap. 8. Multiple Correlation & Discriminant Function Analysis (Read up to p.160 for 5/1/01.) Huck Chap. 19 (read pp. 565-589 for 5/1/01 and rest of chapter for 5/3/01) * Multiple Regression Examples (5/1/01) * Listing a House with a Big Real Estate Agency (Relate this article to the elements of multiple regression-5/1/01) * Spence, S. H. (1981).Validation of social skills of adolescent males in an interview conversation with a previously unknown adult. JABA, 14, 159-168. (Understand how multiple regression was conducted in a series of steps to answer a question about social validation 5/1/01). * Parker, R. M. & Szymanski, E. M. (1999). Recommendations of the APA task force on statistical inference. Rehabilitation Counseling Bulletin, 43, 3-4. (5/3/01) * Read Data Analysis Discriminations-Section B (5/3/01) QUIZ 22 5/3 only, based on readings for both dates. No quiz 5/1 ***May 9, 2001 TEST 4 1:00-2:15PM Room TBA