Statistical Analysis IV: ONEWAY and ANOVA

Abstract

Both of the procedures ONEWAY and ANOVA perform analysis of variance (anova). This statistical test compares the values of a dependent variable for cases which fall into a number of different groups. The independent (between subjects) t-test procedure does the same thing, but only two groups can be compared in each t-test analysis. A one-way analysis of variance can compare two, three or more groups classified in terms of a single independent variable. A two-way analysis of variance compares groups formed by classifying cases simultaneously on two independent variables. If the SPSS/PC+ analysis of variance is to include just one independent variable a one-way anova is performed using either ONEWAY or ANOVA. With two independent variables a two-way anova is performed; and so on for three-way anova, four-way anova, etc. For an anova with two or more (and up to 10) independent variables, the procedure ANOVA must be used.