ANOVA

ANOVA
Analysis of Variance, a hypothesis testing technique allowing you to determine whether the differences between samples are simply due to random sampling errors, or whether there are systematic treatment effects that cause the mean in one group to differ from the mean in another. Excel has a built-in analysis tool for ANOVA.

 

ANOVA can be one-way or two-way. You should use two-way when there is more than one independent (categorical) variable being assessed:

  • One-way ANOVA tests two groups to see if there are differences between them
  • Two-way ANOVA without replication test one group at two different times e.g. before and after taking medication
  • Two-way ANOVA with replication tests two groups who are doing more than one thing e.g. before and after results when the two groups tried different medications
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    ANCOVA (Analysis of Covariance) is a general linear model testing covariance which uses some elements of ANOVA and some elements of regression analysis.

     

    MANOVA (Multivariate Analysis of Variance) is an ANOVA test with multiple dependent variables.

     

     

    General linear models

    An ANOVA procedure used to test hypotheses in statistical experiments, factoring the results of known quantities along with predicted values.