PSYC 217 Study Guide - Final Guide: Null Hypothesis, Confidence Interval, Effect Size
Document Summary
Cozby chapter 13- understanding research results: statistical inference. Need to calc value of t from obtained data. Evaluate tobtained in terms of sampling distribution of t based on null (tcritical) if significance, 0. 05, get tcritical if tobtained has low probability of occurrence (0. 05>), null rejected: a ratio tobtained>tcritical. Degrees of freedom= n1 + n2 -2. One-tailed vs two-tailed tests research hypothesis either. Specified a direction of difference between the groups (1-tailed) Did not specific predicted direction of difference (2-tailed) F test (analysis of variance: extension of t test, *more than 2 levels of an iv, factorial design (2+ ivs, ratio of 2 types of variance: Systematic variance= *deviation fo group means from grand mean small when differences between means is small and increases as group mean differences increase. Error variance= *deviation of individual scores in each group from their respective group means: *larger f= more significant.
