# PSY202H1 Study Guide - Final Guide: Variance, Analysis Of Variance, Pearson Product-Moment Correlation Coefficient

## Document Summary

Larger the mean differences between treatments, larger f-ratio. The definition of the within treatment variance can be divide into individual differences and other error. The error variance: no treatment effects and no individual difference. For example, the flaws in the tool used to measure something could be included in the within- treatment effect. (the flaw of the tool could also be one of the factor in the between treatment variance) Because we do not want to have an inflated experimentwise alpha level. Th population variance for each of the treatment groups are equal and the treatment effect is consistent for all subjects. Because when the sample n = 2, there are 0 degree of freedom, 2 points can fit perfectly on a straight line. Thus, the sample correlation is free to vary only when the data sets contain more than 2 points.