PSYC3042 Lecture Notes - Lecture 8: Confounding, Pocket Cube, Sphericity
Document Summary
2 vs. sensitivity vs. generality: introducing control, distinguishing confounds and limitations on generality and sensitivity. Sphericity the variances of the differences between each pair of levels of a within p-s iv should be equal, so it comapres difference values w1-w2; w1-w3 etc. Not applicable when iv has only 2 levels as in pre-post design. Because with one set of difference scores, there is nothing to compare those difference scores against to indicate a violation of sphericity. Spericity can be violated due to floor or ceiling compression also a 2x2 design or. 2x2x2 design are most likely to violate sphericity. Can be found targeting the method section of the paper. Person variable confounds characteristics and prior experiences of participants that vary systematically. Testing confounds a testing confound occurs when contamination of the post-test data by an effect of the pre-test provides an alternative explanation for the results.
