PSYC 2017 : PSYC 2017 FINAL REVIEW
Document Summary
The goal of descriptive statistics is to describe sample data, and can be contrasted with inferential statistics where the goal is to make inferences about populations from sample data. Variability: low = small standard deviation, medium, high = large standard deviation. The z-score indicates how far above or below a raw score is from its mean in standard deviation units. (ex. A score of +1. 00 indicates a raw score that is one standard deviation unit above the mean. ) Unstandardized difference between means is a comparison of mean differences between levels of a categorical independent variable. Cohen"s d is the difference between two means in standard deviation; it is a common measure of effect size. The magnitude or strength of a relationship between variables is the effect size indicator. The correlation coefficient is the numerical representation of the strength and direction of the relationship between two variables. A positive correlation indicates that the two variables vary together in the same direction.