ANOVA

### ANOVA

Analysis of variance (ANOVA) is used to examine the differences between group means. In addition to determining that differences exist among the means, ANOVA tools in Origin provide multiple means comparisons in order to identify which particular means are different.

### One-Way, Two-Way and Three-Way ANOVA

One-way, two-way and three-way ANOVA consider a completely randomized design for an experiment.

• One-Way ANOVA
One-way ANOVA compares three or more levels within one factor.

• Two-Way ANOVA
Two-way ANOVA is useful to compare the effect of multiple levels of two factors. Two way ANOVA is an appropriate method to analyze the main effects of and interactions between two factors.

• Three-Way ANOVA PRO
Three-way ANOVA ests for interaction effects between three independent variables on a continuous dependent variable (i.e., if a three-way interaction exists).

### Repeated Measure ANOVA PRO

The repeated measures design is also known as a within-subject design. It has the same subjects performed under every condition.

Repeated measure ANOVA tools in Origin consider three possible designs:

• One-way Repeated Measures
ANOVA with one repeated-measures factor.

• Two-way Repeated Measures
ANOVA with two repeated-measures factor.

• Two-way Mixed-Design
The two-way mixed-design is also known as two way split-plot design (SPANOVA). It is ANOVA with one repeated-measures factor and one between-groups factor.

### Means Comparison / Post-hoc Tests

The mean comparison tests in ANOVA, also known as Post Hoc tests, are useful to perform additional comparisons of subsets of the means.

All four ANOVA tools in Origin, one and two-way ANOVA, one and two-way repeated measure ANOVA provides seven means comparison tests:

• Tukey
• Bonferroni
• Dunn-Sidak
• Fisher LSD
• Sheff¨¦
• Holm-Bonferroni
• Holm-Sidak