Analysis of Variance (ANOVA) Post-Hoc Analysis

Word check When I talk about between groups variability, what am I talking about? What about within groups variability? What does SST represent? SSE? In general, how are these calculated? What does MS (either within or between) represent? What does the F ratio represent?

Regression and ANOVA http://www.stat.yale.edu/Courses/1997-98/101/anovareg.htm

Tukey’s Method Compares the means for each pair of factor levels using a family error rate to control the rate of type I error. often called familywise error rate or experimentwise error rate The family error rate is the probability of making one or more type I errors for the entire set of comparisons. Tukey's method adjusts the individual confidence level, based on the family error rate you choose.

Multiple Comparisons These are confidence intervals Do the pairs of numbers capture 0? If so… no significant difference in the means (we fail to reject the null hypothesis) If not, we can conclude that the mean for one expression exceeds the mean for the other