Welcome Statistical Methods and Data analysis PSY-301

Course Skills Objectives n Computer Analysis of Data l Using SPSS (PASW) u Statistical Package for the Social Sciences n Interpretation of Results l What do results mean? l What conclusions can be drawn? n Communication l Written, oral, and graphical l Effectively communicate results and influence others ~

Statistics are Tools n Tools that: l are useful l don’t tell truth or lies l Are used by people n Statistics help us make decisions l About variable & fluctuating information l Guided by human wisdom & values ~

Application of Statistics n Opinion/Political Polls l Influence public policy n Benefits vs. safety risks l new drugs / medical procedures l Epidemiology (autism & vaccines) n Environmental issues l Emissions control vs. economics n Courts l Sentencing equity ~

Statistics & Psychology n The Science of Statistics l a set of methods & rules for organizing, summarizing, and interpreting information n The Science of Psychology l Behavior & cognitive processes l describe, explain, predict & control l Relationships between variables l Similarities & Differences ~

An observation on human behavior: You see, really and truly, apart from the things anyone can pick up (the dressing and the proper way of speaking, and so on), the difference between a lady and a flower girl is not how she behaves, but how she’s treated. I shall always be a flower girl to Professor Higgins because he always treats me as a flower girl, and always will; but I know I can be a lady to you because you treat me like a lady, and always will. Eliza Doolittle in George Bernard Shaw’s Pygmalion

Testing the Pygmalion Effect n Can the expectations of others influence one’s behavior? l Rosenthal & Jacobson (1968) n Predictor Variable l Teacher’s expectation of student l “bloomer” or “non-bloomer” n Outcome Variable l Change in student IQ score ~

Rosenthal & Jacobson (1968) n “Oak School” 2d graders given new test u “Harvard Test of Inflected Acquisition”: HTIA l predicts learning spurts in top 20% l Informed only teacher of scores n End of school year test again l Test Of General Abilities: IQ test l HTIA actually was TOGA u pretest - posttest n Operational definition l Measure change in IQ scores ~

Rosenthal & Jacobson (1968) n Conclusions not readily apparent l “real” differences or normal variation l Sampling error? n Descriptive Statistics: Average IQ change l Bloomers: 16.5 l Nonbloomers: 7.0 n Inferential statistics l Did bloomers improve significantly more n Experimenter Bias in research l Importance of control ~

Why Statistics? n Tools to critically evaluate information n Help account for variations l differences & similarities n Psychology goals l describe, explain, predict, control n Statistics AID decision-making l Meaningful results from fluctuating data ~