Lecture 1 Outline: Thu, Sep 4 Introduction/Syllabus Course outline Some useful guidelines Case studies and 1.1.2

Course objectives Understand distinctions between various types of studies (e.g., observational studies, controlled experiments), the questions they can address and what types of statistical methods are appropriate for analyzing them. Statistical tools: two sample methods, several sample methods (ANOVA), multiple comparisons, simple linear regression, multiple linear regression Hands on experience analyzing data and computing with data (using JMP). Interpretation and communication of results

Guidelines The lectures will be used to present the basic ideas, illuminate key concepts, present examples and have class discussion. You are responsible for both the material presented in lecture and the reading. The reading for each lecture is on the lecture schedule (check web page for updates to schedule).

Guidelines (Contd.) At the end of each chapter, the book contains conceptual questions with answers which you should use to test your understanding of material. JMP-IN –Used extensively for assignments. –Familiarity with output for exams –Recommended JMP-IN text is a good reference

Guidelines (Contd.) The final grade is determined based on the assignments, midterms, final project and final. Preparation for exams –Review lectures. –Review reading. –Review assignments.

Guidelines (Contd.) Feedback on lecture style, assignments, other aspects of course is encouraged. Constant interaction encouraged to better understand the material.

Two Sample Problems Compare the response variables of two groups: –Two distinct populations (e.g, the opinions of men vs. women on President Bush’s job performance) –Two different treatments applied to one population (e.g., the effect of taking a drug vs. a placebo on depression).

Case Study 1.1.1: Motivation and Creativity Broad scientific questions of interest: Do grading systems promote creativity in students? Do ranking systems and awards increase productivity among employees? Do rewards and praise stimulate children to learn? Experiment: Students in a creative writing class were randomly assigned to one of two groups. One received an “intrinsic” and the other an “extrinsic” questionnaire. Afterwards, they wrote Haiku poems that were scored for creativity.

Statistical Analysis Specific question of interest: Is there any evidence that creativity scores tend to be affected by the type of motivation (intrinsic/extrinsic) induced by the questionnaire? Statistical tools for addressing this question –Graphical methods –Hypothesis test (p-value) –Confidence interval

Things to Think About Can we infer that the difference in creativity scores was caused by the difference in motivational questionnaires? The poems were given to judges in random order. Why was that important? To what extent does this experiment address the real scientific question of interest, do external incentives promote creativity?

Case study 1.1.2: Sex discrimination in employment Legal/scientific question of interest: Did a bank discriminatorily pay higher starting salaries to men than women? The data: Starting salaries were available for all male and female entry-level clerical employees of the Harris bank. Specific question: Did male starting salaries tend to be larger than female starting salaries? (more so than could be explained by chance?)

Things to think about Can we infer that discrimination has occurred on the basis of the evidence that men received larger starting salaries than women? Suppose we also had available information about education and experience of the employees. How could we use this information? Would it allow us to infer that discrimination has occurred?