Teaching Statistical Concepts with Activities, Data, and Technology Beth L. Chance and Allan J. Rossman Dept of Statistics, Cal Poly – San Luis Obispo Goals Acquaint you with recent recommendations and ideas for teaching introductory statistics Including some very “modern” approaches On top of some issues we consider essential Provide specific examples and activities that you might plug into your courses Point you toward online and print resources that might be helpful APSA Conference, Sept 2010 2 Schedule Introductions Opening Activity Activity Sessions Data Collection Data Analysis << lunch>> Randomness Statistical Inference Resources and Assessment Q&A, Wrap-Up APSA Conference, Sept 2010 3 Requests Participate in activities 23 of them! Play role of student We’ll skip/highlight some Good student, not disruptive student! Feel free to interject comments, questions APSA Conference, Sept 2010 4 GAISE Emphasize statistical literacy and develop statistical thinking Use real data Stress conceptual understanding rather than mere knowledge of procedures Foster active learning in the classroom Use technology for developing conceptual understanding and analyzing data Use assessments to improve and evaluate student learning www.amstat.org/education/gaise APSA Conference, Sept 2010 5 Opening Activity Naughty or nice? (Nature, 2007) Videos: http://www.yale.edu/infantlab/socialevaluation/ Helper-Hinderer.html Flip 16 coins, one for each infant, to decide which toy you want to play with (heads=helper) Coin Tossing Applet: http://www.rossmanchance.com/applets APSA Conference, Sept 2010 6 3S Strategy Statistic Simulate “Could have been” distribution of data for each repetition (under null model) “What if” distribution of statistics across repetitions (under null model) Strength of evidence Reject vs. plausible APSA Conference, Sept 2010 7 Summary Use real data/scientific studies Stress conceptual understanding Idea of p-value on day 1/in one day! Foster active learning Emphasize the process of statistical investigation You are a dot on the board Use technology Could this have happened “by chance alone”? What if only 10 infants had picked the helper? APSA Conference, Sept 2010 8 Data Collection Activities: Activity 2: Sampling Words Circle 10 representative words in the passage Record the number of letters in each word Calculate the mean number of letters in your sample Dotplot of results… APSA Conference, Sept 2010 9 Sampling Words The population mean of all 268 words is 4.295 letters How many sample means were too high? Why do you think so many sample means are too high? APSA Conference, Sept 2010 10 Sampling Words “Tactile” simulation Ask students to use computer or random number table to take simple random samples Determine the sample mean in each sample Compare the distributions APSA Conference, Sept 2010 11 Sampling Words Java applet www.rossmanchance.com/applets/ Select “Sampling words” applet Select individual sample of 5 words Repeat Select 98 more samples of size 5 Explore the effect of sample size Explore the effect of population size APSA Conference, Sept 2010 12 Morals: Selecting a Sample Random Sampling eliminates human selection bias so the sample will be fair and unbiased/representative of the population. While increasing the sample size improves precision, this does not decrease bias. APSA Conference, Sept 2010 13 Activity 3: Night Lights and Near-Sightedness Quinn, Shin, Maguire, and Stone (1999) 479 children Did your child use a night light (or room light or neither) before age 2? Eyesight: Hyperopia (far-sighted), emmetropia (normal) or myopia (nearsighted)? APSA Conference, Sept 2010 14 Night Lights and Near-Sightedness Darkness Night light Room light Nearsighted 18 78 41 Normal refraction 114 115 22 Far-sighted 40 39 12 APSA Conference, Sept 2010 15 Night Lights and Near-Sightedness 100% 90% 80% 70% 60% Far-sighted 50% Normal refraction Near-sighted 40% 30% 20% 10% 0% Darkness APSA Conference, Sept 2010 Night light Room light 16 Morals: Confounding Students can tell you that association is not the same as causation! Need practice clearly describing how confounding variable Is linked to both explanatory and response variables Provides an alternative explanation for observed association APSA Conference, Sept 2010 17 Activity 4: Have a Nice Trip Can instruction in a recovery strategy improve an older person’s ability to recover from a loss of balance? 12 subjects have agreed to participate in the study Assign 6 people to use the lowering strategy and 6 people to use the elevating strategy What does “random assignment” gain you? APSA Conference, Sept 2010 18 Have a Nice Trip Randomizing subjects applet How do the two groups compare? APSA Conference, Sept 2010 19 Morals Goal of random assignment is to be willing to consider the treatment groups equivalent prior to the imposition of the treatment(s). This allows us to eliminate all potential confounding variables as a plausible explanation for any significant differences in the response variable after the treatments are imposed. APSA Conference, Sept 2010 20 Activity 5: Cursive Writing Does using cursive writing cause students to score better on the SAT essay? APSA Conference, Sept 2010 21 Morals: Scope of Conclusions The Statistical Sleuth, Ramsey and Schafer Allocation of units to groups Random sampling By random assignment No random assignment A random sample is selected from one population; units are then randomly assigned to different treatment groups Random samples are selected from existing distinct populations A groups of study units is found; units are then randomly assigned to treatment groups Collections of available units from distinct groups are examined Inferences to populations can be drawn Selection of units Not random sampling Cause and effect conclusions can be drawn APSA Conference, Sept 2010 22 Activity 6: Memorizing Letters You will be asked to memorize as many letters as you can in 20 seconds, in order, from a sequence of 30 letters Variables? Type of study? Comparison? Random assignment? Blindness? Random sampling? More to come … APSA Conference, Sept 2010 23 Morals: Data Collection Quick, simple experimental data collection Highlighting critical aspects of effective study design Can return to the data several times in the course APSA Conference, Sept 2010 24 Data Analysis Activities Activity 7: Matching Variables to Graphs Which dotplot belongs to which variable? Justify your answer APSA Conference, Sept 2010 25 Morals: Graph-sense Learn to justify opinions Consistency, completeness Appreciate variability Be able to find and explain patterns in the data APSA Conference, Sept 2010 26 Activity 8: Rower Weights 2008 Men’s Olympic Rowing Team APSA Conference, Sept 2010 27 Rower Weights Mean 197.96 201.17 209.65 Full Data Set Without Coxswain Without Coxswain or lightweight rowers With heaviest at 249 210.65 With heaviest at 429 219.70 Resistance.... APSA Conference, Sept 2010 Median 205.00 207.00 209.00 209.00 209.00 28 Morals: Rower Weights Think about the context “Data are numbers with a context” -Moore Know what your numerical summary is measuring Investigate causes for unusual observations Anticipate shape APSA Conference, Sept 2010 29 Activity 9: Cancer Pamphlets Researchers in Philadelphia investigated whether pamphlets containing information for cancer patients are written at a level that the cancer patients can comprehend APSA Conference, Sept 2010 30 Cancer Pamphlets 0.3 0.25 patients pamphlets proportion 0.2 0.15 0.1 0.05 above 12 12 11 10 9 8 7 6 5 4 3 under 3 0 level APSA Conference, Sept 2010 31 Morals: Importance of Graphs Look at the data Think about the question Numerical summaries don’t tell the whole story “median isn’t the message” - Gould APSA Conference, Sept 2010 32 Activity 10: Draft Lottery Draft numbers (1-366) were assigned to birthdates in the 1970 draft lottery Find your draft number Any 225s? APSA Conference, Sept 2010 33 Draft Lottery APSA Conference, Sept 2010 34 Draft Lottery month median January 211.0 February 210.0 March 256.0 April 225.0 May 226.0 June 207.5 APSA Conference, Sept 2010 month median July 188.0 August 145.0 September 168.0 October 201.0 November 131.5 December 100.0 35 Draft Lottery APSA Conference, Sept 2010 36 Morals: Statistics matters! Summaries can illuminate Randomization can be difficult APSA Conference, Sept 2010 37 Activity 11: Televisions and Life Expectancy Is there an association between the two variables? r = .743 So sending televisions to countries with lower life expectancies would cause their inhabitants to live longer? APSA Conference, Sept 2010 38 Morals: Confounding Don’t jump to conclusions from observational studies The association is real but consider carefully the interpretation of graph and wording of conclusions (and headlines) APSA Conference, Sept 2010 39 Activity 6 Revisited (Memorizing Letters) Produce, interpret graphical displays to compare performance of two groups Does research hypothesis appear to be supported? Any unusual features in distributions? APSA Conference, Sept 2010 40 Lunch! Questions? Write down and submit any questions you have thus far on the statistical or pedagogical content… APSA Conference, Sept 2010 41 Exploring Randomness Activity 12: Random Babies Last Names Jones Miller Smith Williams APSA Conference, Sept 2010 First Names Jerry Marvin Sam Willy 42 Random Babies Last Names Jones Miller Smith Williams APSA Conference, Sept 2010 First Names Marvin 43 Random Babies Last Names Jones Miller Smith Williams APSA Conference, Sept 2010 First Names Marvin Willy 44 Random Babies Last Names Jones Miller Smith Williams APSA Conference, Sept 2010 First Names Marvin Willy Sam 45 Random Babies Last Names Jones Miller Smith Williams APSA Conference, Sept 2010 First Names Marvin Willy Sam Jerry 46 Random Babies Last Names Jones Miller Smith Williams APSA Conference, Sept 2010 First Names Marvin Willy Sam 1 match Jerry 47 Random Babies Long-run relative frequency Applet: www.rossmanchance.com/applets/ “Random Babies” APSA Conference, Sept 2010 48 Random Babies: Mathematical Analysis 1234 1243 1324 1342 1423 1432 2134 2143 2314 2341 2413 2431 3124 3142 3214 3241 3412 3421 4123 4132 4213 4231 4312 4321 APSA Conference, Sept 2010 49 Random Babies 1234 4 2134 2 3124 1 4123 0 1243 1324 2 2 2143 2314 0 1 3142 3214 0 2 4132 4213 1 1 APSA Conference, Sept 2010 1342 1 2341 0 3241 1 4231 2 1423 1 2413 0 3412 0 4312 0 1432 2 2431 1 3421 0 4321 0 50 Random Babies 0 matches: 9/24=3/8 1 match: 8/24=1/3 2 matches: 6/24=1/4 3 matches: 0 4 matches: 1/24 APSA Conference, Sept 2010 51 Morals: Treatment of Probability Goal: Interpretation in terms of long-run relative frequency, average value First simulate, then do theoretical analysis 30% chance of rain… Able to list sample space Short cuts when are actually equally likely Simple, fun applications of basic probability APSA Conference, Sept 2010 52 Activity 13: AIDS Testing ELISA test used to screen blood for the AIDS virus Sensitivity: P(+|AIDS)=.977 Specificity: P(-|no AIDS)=.926 Base rate: P(AIDS)=.005 Find P(AIDS|+) Initial guess? Bayes’ theorem? Construct a two-way table for hypothetical population APSA Conference, Sept 2010 53 AIDS Testing Positive Negative AIDS No AIDS Total APSA Conference, Sept 2010 Total 1,000,000 54 AIDS Testing Positive Negative AIDS No AIDS Total APSA Conference, Sept 2010 Total 5,000 995,000 1,000,000 55 AIDS Testing AIDS No AIDS Total APSA Conference, Sept 2010 Positive Negative 4885 115 Total 5,000 995,000 1,000,000 56 AIDS Testing Positive Negative Total AIDS 4885 115 5,000 No AIDS 73,630 921,370 995,000 Total 1,000,000 APSA Conference, Sept 2010 57 AIDS Testing Positive Negative Total AIDS 4885 115 5,000 No AIDS 73,630 921,370 995,000 Total 78,515 921,485 1,000,000 APSA Conference, Sept 2010 58 AIDS Testing Positive Negative Total AIDS 4885 115 5,000 No AIDS 73,630 921,370 995,000 Total 78,515 921,485 1,000,000 P(AIDS|+) = 4885/78,515=.062 APSA Conference, Sept 2010 59 AIDS Testing Positive Negative Total AIDS 4885 115 5,000 No AIDS 73,630 921,370 995,000 Total 78,515 921,485 1,000,000 P(AIDS|+) = 4885/78,515=.062 P(No AIDS|-) = 921,370/921,485 =.999875 APSA Conference, Sept 2010 60 Morals: Surprise Students! Intuition about conditional probability can be very faulty Confront misconception head-on Conditional probability can be explored through two-way tables Treatment of formal probability can be minimized APSA Conference, Sept 2010 61 Activity 14: Reese’s Pieces APSA Conference, Sept 2010 62 Reese’s Pieces Take sample of 25 candies Sort by color Calculate the proportion of orange candies in your sample Construct a dotplot of the distribution of sample proportions APSA Conference, Sept 2010 63 Reese’s Pieces Turn over to technology Reeses Pieces applet (www.rossmanchance.com/applets/) APSA Conference, Sept 2010 64 Morals: Sampling Distributions Study randomness to develop intuition for statistical ideas Not probability for its own sake Always precede technology simulations with physical ones Apply more than derive formulas APSA Conference, Sept 2010 65 Activity 15: Which Tire? Left Front Right Front Left Rear Right Rear APSA Conference, Sept 2010 66 Which Tire? People tend to pick “right front” more than ¼ of the time Variable = which tire pick Categorical (binary) How often would we get data like this by chance alone? Determine the probability of obtaining at least as many “successes” as we did if there were nothing special about this particular tire. APSA Conference, Sept 2010 67 Which Tire? Let p = proportion of all … who pick right front H0: p = .25 Ha: p > .25 .32 .25 Test statistic z = .25(.75) / n p-value = Pr(Z>z) How does this depend on n? Test of Significance Calculator APSA Conference, Sept 2010 68 Which Tire? n 50 100 150 400 1000 APSA Conference, Sept 2010 z-statistic 1.14 1.62 1.98 3.23 5.11 p-value .127 .053 .024 .001 .000… 69 Morals: Formal Statistical Inference Fun simple data collection Effect of sample size hard to establish result with small samples Never “accept” null hypothesis APSA Conference, Sept 2010 70 Activity 16: Kissing the Right Way Biopsychology observational study Güntürkün (2003) recorded the direction turned by kissing couples to see if there was also a rightsided dominance. APSA Conference, Sept 2010 71 Kissing the Right Way Is 1/2 a plausible value for p, the probability a kissing couple turns right? Coin Tossing applet Is 2/3 a plausible value for p, the probability a kissing couple turns right? Is the observed result in the tail of the “what if” distribution? APSA Conference, Sept 2010 72 Kissing the Right Way Determine the plausible values for p, the probability a kissing couple turns right… The values that produce an approximate pvalue greater than .05 are not rejected and are therefore considered plausible values of the parameter. The interval of plausible values is sometimes called a confidence interval for the parameter. APSA Conference, Sept 2010 73 Kissing the Right Way How does this compare to estimate + margin of error? pˆ (1 pˆ ) pˆ 2 n Or the even simpler approximation? 1 pˆ n APSA Conference, Sept 2010 74 Morals: Kissing the Right Way Interval estimation as (more?) important as significance Confidence interval as set of plausible (not rejected) values Interpretation of margin-of-error APSA Conference, Sept 2010 75 Activity 17: Reese’s Pieces Revisited Calculate 95% confidence interval for p from your sample proportion of orange Does everyone have same interval? Does every interval necessarily capture p? What proportion of class intervals would you expect? Simulating Confidence Intervals applet What percentage of intervals succeed? Change confidence level, sample size APSA Conference, Sept 2010 76 Morals: Reese’s Pieces Revisited Interpretation of confidence level In terms of long-run results from taking many samples Effects of confidence level, sample size on confidence interval APSA Conference, Sept 2010 77 Example 18: Dolphin Therapy Subjects who suffer from mild to moderate depression were flown to Honduras, randomly assigned to a treatment Subject improved Subject did not Total Proportion APSA Conference, Sept 2010 Dolphin therapy 10 5 15 0.667 Control group 3 12 15 0.200 Total 13 17 30 78 Dolphin Therapy Is dolphin therapy more effective than control? Core question of inference: Is such an extreme difference unlikely to occur by chance (random assignment) alone (if there were no treatment effect)? APSA Conference, Sept 2010 79 Some approaches Could calculate test statistic, p-value from approximate sampling distribution (z, chi-square) But it’s approximate But conditions might not hold But how does this relate to what “significance” means? Could conduct Fisher’s Exact Test But there’s a lot of mathematical start-up required But that’s still not closely tied to what “significance” means Even though this is a randomization test APSA Conference, Sept 2010 80 3S Approach Simulate random assignment process many times, see how often such an extreme result occurs Assume no treatment effect (null model) Re-randomize 30 subjects to two groups (using cards) Determine number of improvers in dolphin group Assuming 13 improvers, 17 non-improvers regardless Or, equivalently, difference in improvement proportions Repeat large number of times (turn to computer) Ask whether observed result is in tail of what if distribution Indicating saw a surprising result under null model Providing evidence that dolphin therapy is more effective APSA Conference, Sept 2010 81 Analysis http://www.rossmanchance.com/applets/ Dolphin Study applet APSA Conference, Sept 2010 82 Conclusion Experimental result is statistically significant And what is the logic behind that? Observed result very unlikely to occur by chance (random assignment) alone (if dolphin therapy was not effective) APSA Conference, Sept 2010 83 Morals Re-emphasize meaning of significance and p-value Use of randomness in study Focus on statistical process, scope of conclusions APSA Conference, Sept 2010 84 Activity 19: Sleep Deprivation Does sleep deprivation have harmful effects on cognitive functioning three days later? 21 subjects; random assignment sleep condition deprived unrestricted -16 -8 0 8 16 24 improvement 32 40 Core question of inference: Is such an extreme difference unlikely to occur by chance (random assignment) alone (if there were no treatment effect)? APSA Conference, Sept 2010 85 Sleep Deprivation Simulate randomization process many times under null model, see how often such an extreme result (difference in group medians or means) occurs Start with tactile simulation using index cards Write each “score” on a card Shuffle the cards Randomly deal out 11 for deprived group, 10 for unrestricted group Calculate difference in group medians (or means) Repeat many times (Randomization Tests applet) APSA Conference, Sept 2010 86 Sleep Deprivation Conclusion: Fairly strong evidence that sleep deprivation produces lower improvements, on average, even three days later Justification: Experimental results as extreme as those in the actual study would be quite unlikely to occur by chance alone, if there were no effect of the sleep deprivation APSA Conference, Sept 2010 87 Exact randomization distribution Exact p-value 2533/352716 = .0072 (for difference in means) APSA Conference, Sept 2010 88 Morals: Randomizations Tests Emphasizes core logic of inference Takes advantage of modern computing power Easy to generalize to other statistics APSA Conference, Sept 2010 89 Activity 6 Revisited (Memorizing Letters) Conduct randomization test to assess strength of evidence in support of research hypothesis Enter data into applet Summarize conclusion and reasoning process behind it Does non-significant result indicate that grouping of letters has no effect? APSA Conference, Sept 2010 90 Activity 20: Cat Households 47,000 American households (2007) 32.4% owned a pet cat or the other way around! test statistic: z=-4.29 p-value: virtually zero 99% CI for p: (.31844, .32956) APSA Conference, Sept 2010 91 Morals: Limits of statistical significance Statistical significance is not practical significance Especially with large sample sizes Accompany significant tests with confidence intervals whenever possible APSA Conference, Sept 2010 92 Activity 21: Female Senators 17 women, 83 men in 2010 95% CI for p: = .170 + .074 = (.096, .244) APSA Conference, Sept 2010 93 Morals: Limitations of Inference Always consider sampling procedure Randomness is key assumption Garbage in, garbage out Inference is not always appropriate! Sample = population here APSA Conference, Sept 2010 94 Activity 22: Game Show Prices Sample of 208 prizes from The Price is Right Examine a histogram 99% confidence interval for the mean Technical conditions? What percentage of the prizes fall in this interval? Why is this not close to 99%? APSA Conference, Sept 2010 95 Morals: Cautions/Limitations Prediction intervals vs. confidence intervals Constant attention to what the “it” is APSA Conference, Sept 2010 96 Activity 23: Government Spending 2004 General Social Survey: Is there an association between American adults’ opinion on federal government spending on the environment and political inclinations? APSA Conference, Sept 2010 97 Government Spending Descriptive analysis Liberal Moderate Conservative Total Too Much 1 17 32 50 About Right 27 80 91 198 Too Little 127 158 113 398 Total 155 255 236 646 APSA Conference, Sept 2010 98 Government Spending Inferential analysis – 3S approach 1. Chi-square statistic 2. Simulate sampling distribution of chi-square test statistic under null hypothesis of no association Randomly mix up political inclinations, determine “could have been” table Repeat many times and examine “what if” distribution of chi-square values under null hypothesis APSA Conference, Sept 2010 99 Government Spending 3. Strength of evidence Is observed chi-square value in tail of distribution? Summarize: What conclusions should be drawn? Very statistically significant Not cause and effect Ok to generalize to adult Americans APSA Conference, Sept 2010 100 Government Spending What about federal spending on the space program? More or less evidence of association? Larger or smaller p-value? APSA Conference, Sept 2010 101 General Advice Emphasize the process of statistical investigations, from posing questions to collecting data to analyzing data to drawing inferences to communicating findings Use simulation, both tactile and technology-based, to explore concepts of inference and randomness Draw connections between how data are collected (e.g., random assignment, random sampling) and scope of conclusions to be drawn (e.g., causation, generalizability) Use real data from genuine studies, as well as data collected on students themselves Present important studies (e.g., draft lottery) and frivolous ones (e.g., flat tires) and especially studies of issues that are directly relevant to students (e.g., sleep deprivation) APSA Conference, Sept 2010 102 General Advice (cont.) Lead students to “discover” and tell you important principles (e.g., association does not imply causation) Keep in mind the research question when analyzing data Graphical displays can be very useful Summary statistics (measures of center and spread) are helpful but don’t tell whole story; consider entire distribution Develop graph-sense, number-sense by always thinking about context Use technology to reduce the burden of rote calculations, both for analyzing data and exploring concepts Emphasize cautions and limitations with regard to inference procedures APSA Conference, Sept 2010 103 Implementation Suggestions Take control of the course Collect data from students Encourage predictions from students Allow students to discover/tell you findings Precede technology simulations with tactile Promote collaborative learning Provide lots of feedback Follow activities with related assessments Intermix lectures with activities Don’t underestimate ability of activities to teach materials Have fun! APSA Conference, Sept 2010 104 Suggestion #1 Take control of the course Not “control” in usual sense of standing at front dispensing information But still need to establish structure, inspire confidence that activities, self-discovery will work Be pro-active in approaching students Don’t wait for students to ask questions of you Ask them to defend their answers Be encouraging Instructor as facilitator/manager APSA Conference, Sept 2010 105 Suggestion #2 Collect data from students Leads them to personally identify with data, analysis; gives them ownership Collect anonymously Can do out-of-class E.g., matching variables to graphs APSA Conference, Sept 2010 106 Suggestion #3 Encourage predictions from students Fine (better…) to guess wrong, but important to take stake in some position Directly confront common misconceptions Have to “convince” them they are wrong (e.g., Gettysburg address) before they will change their way of thinking E.g., AIDS Testing APSA Conference, Sept 2010 107 Suggestion #4 Allow students to discover, tell you findings E.g., Televisions and life expectancy “I hear, I forget. I see, I remember. I do, I understand.” -- Chinese proverb APSA Conference, Sept 2010 108 Suggestion #5 Precede technology simulations with tactile/ concrete/hands-on simulations Enables students to understand process being simulated Prevents technology from coming across as mysterious “black box” E.g., Gettysburg Address (actual before applet) APSA Conference, Sept 2010 109 Suggestion #6 Promote collaborative learning Students can learn from each other Better yet from “arguing” with each other Students bring different background knowledge E.g., Matching variables to graphs APSA Conference, Sept 2010 110 Suggestion #7 Provide lots of feedback Danger of “discovering” wrong things Provide access to “model” answers after the fact Could write “answers” on board Could lead discussion/debriefing afterward APSA Conference, Sept 2010 111 Suggestion #8 Follow activities with related assessments Or could be perceived as “fun and games” only Assessments encourage students to grasp concept Require summary paragraphs in their own words Clarify early (e.g., quizzes) that they will be responsible for the knowledge Can also help them to understand concept E.g., fill in the blank p-value interpretation APSA Conference, Sept 2010 112 Suggestion #9 Inter-mix lectures with activities One approach: Lecture on a topic after students have performed activity Another approach: Engage in activities toward end of class period Students better able to process, learn from lecture having grappled with issues themselves first Often hard to re-capture students’ attention afterward Need frequent variety APSA Conference, Sept 2010 113 Suggestion #10 Do not under-estimate ability of activities to “teach” material No dichotomy between “content” and “activities” Some activities address many ideas E.g. “Gettysburg Address” activity Population vs. sample, parameter vs. statistic Bias, variability, precision Random sampling, effect of sample/population size Sampling variability, sampling distribution, Central Limit Theorem (consequences and applicability) APSA Conference, Sept 2010 114 Suggestion #11 Have fun! APSA Conference, Sept 2010 115 Assessment Advice Two sample final exams Carefully match the course goals Be cognizant of any review materials you have given the students Use real data and genuine studies Provide students with guidance for how long they should spend per problem Use multiple parts to one context but aim for independent parts (if a student cannot answer part (a) they may still be able to answer part (b)) Use open-ended questions requiring written explanation Aim for at least 50% conceptual questions rather than pure calculation questions (Occasionally) Expect students to think, integrate, apply beyond what they have learned. Sample guidelines for student projects APSA Conference, Sept 2010 116 Promoting Student Progress Document and enhance student learning Element of instruction Interactive feedback loop Diagnostic with indicators for change Throughout the course To student and instructor Encourage self-evaluation Multiple indicators APSA Conference, Sept 2010 117 Student Projects Best way to demonstrate to students the practice of statistics Experience the fine points of research Experience the “messiness” of data From beginning to end Formulation and Explanation Constant Reference statweb.calpoly.edu/bchance/stat217/projects.html APSA Conference, Sept 2010 118 Resources www.causeweb.org APSA Conference, Sept 2010 119 Resources GAISE reports APSA Conference, Sept 2010 120 Resources TeachingWithData.org APSA Conference, Sept 2010 121 Resources Inter-University Consortium for Political and Social Research (ICPSR) APSA Conference, Sept 2010 122 Resources www.rossmanchance.com/applets/ http://statweb.calpoly.edu/csi/ APSA Conference, Sept 2010 123 Resources https://app.gen.umn.edu/artist/ APSA Conference, Sept 2010 124 Resources http://lib.stat.cmu.edu/DASL/ www.amstat.org/publications/jse/ /jse_data_archive.html APSA Conference, Sept 2010 125 Background Readings Guidelines for teaching introductory statistics Reflections on what distinguishes statistical content and statistical thinking Educational research findings and suggestions related to teaching statistics Collections of resources and ideas for teaching statistics Suggestions and resources for assessing student learning in statistics APSA Conference, Sept 2010 126 Thanks very much! Questions, comments? bchance@calpoly.edu arossman@calpoly.edu APSA Conference, Sept 2010 127 My Syllabus Briefly W1: Collecting Data W2: Graphical/Numerical W3: Normal Project 1 W4: Exam 1 Project 2 W5: Probability W6: Sampling Distributions W7: Inference W8: Inference APSA Conference, Sept 2010 128 My Syllabus Briefly W9: Two Samples W10: Exam II Project 3 W11: Two variables W12: Inference for Regression W13: Two-way Tables Project 4 W14: ANOVA W15: Presentations APSA Conference, Sept 2010 129 Non-simulation approach Exact randomization distribution Hypergeometric distribution Fisher’s Exact Test p-value = 13 17 13 17 13 17 13 17 = .0127 10 5 11 4 12 3 13 2 30 Distribution Plot 15 Hypergeometric, N=30, M=13, n=15 0.30 0.25 Probability 0.20 0.15 0.10 0.05 0.0127 0.00 APSA Conference, Sept 2010 3 X 10 130