The second edition of this book provides a conceptual understanding of analysis of variance. It outlines methods for analysing variance that are used to study the effect of one or more nominal variables on a dependent, interval level variable. The book presumes only elementary background in significance testing and data analysis.
The choice between a fixed or a random model depends on whether we have data on all the categories of the explanatory variables or not. If[Page 79] we have data for all the categories, we use a fixed model; and if we have data for a sample of categories, we use a random ...