Session 3b Flashcards
One-way ANOVA purpose
To test whether the means of k (≥ 2) populations significantly differ.
what does the F -statistic (or F ratio) do
We can assess the relative magnitude of the two different parts of variance
One-way ANOVA needs sample estimates of what to do the computatiojns
MSM and MSR
An analogy: Note that sample variance is obtained by dividing the Sum of Squared deviations (SS) by its degrees of freedom.
Total SS (=variation) can be divided into two parts:
SSM
SSR
what is SSm
Variation due to the model, or between-group variation
variation between the sample means (across levels of the IV)
what is SSR
Residual variation, or within-group variation
variation that exists among the observations within a particular group, not explained by the IV
what is SST
the aggregate variation/dispersion of individual observations across groups (the sum of SSM and SSR)
for SSM, If there more variation in population means, we should expect what
more variability between sample means
for SSR, what do you do
Summing the variation within each group and then adding over all groups
MST , MSM , and MSR are often called what
the total, model (between-group), and residual (within-group) Mean Squares, respectively
what are the 2 ways to calculate effect size
Pearson’s correlation coefficient
Omega
what is Pearson’s correlation coefficient
Also called η (eta) or a correlation ratio
a little biased
what is Omega
similar to Pearson’s but UNbiased
what is Grand Mean (X) (bar over X)
The average of all the values when the factor is ignored
