PSY-B - Psychology PSY-B 311 Lecture Notes - Lecture 12: Null Hypothesis, Type I And Type Ii Errors, Jury Trial

• School: IUPUI
• Department: PSY-B - Psychology
• Course: PSY-B - Psychology PSY-B 311
• Professor: Robert Stewert

Document Summary

B311 lecture 12 error variance due to treatment iv. Total variance = systematic variance + unsystematic variance. The experiment works : if the total variance includes systematic and error variance. The experiment does not work : if the total variance does not include systematic variance; i. e. , is error variance only. Random variations in the experimental setting and procedure. Error variance: e. g. , a simple experiment with 2 groups. To determine error variance we can calculate the variance within a single group. Because all ps in a group received the same treatment: We know this variability is not due to manipulating the iv (systematic variance). The variance within each group is pure error variance. If the iv had an effect on the dv: The means for the two groups will differ. The means for two groups will likely be different even if the ps in each group got the same treatment.