PS296 Lecture Notes - Lecture 18: Squared Deviations From The Mean
Document Summary
The random variation in scores around their own group mean. This denominator easier to calculate than between groups variance. N = total number of participants k = number of groups (levels, conditions) If we have 3 groups with 5 people in each, we have 15 participants and 3 conditions. N = 15, k = 3 df = 12: calculate sum of squares for each individual group. X xbar, then square it, then add them up: then we add up the sum of squares for all groups. If the sums of squares for 3 the groups are 6, 6, and 4. Our total is 16 sw = 16. 000 / 12 = 1. 333. 1. 333 represents our best estimate of how participants randomly vary from each other on this test. The variance in group means around the grand mean. Can also be written as x with 2 bars above it. The mean of all observations in a study.
