iSixSigma

Two-Way ANOVA vs GLM

Six Sigma – iSixSigma Forums Old Forums General Two-Way ANOVA vs GLM

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • #52941

    Arap
    Participant

    Can anyone enlighten me to any advantages of using Two-Way ANOVA over GLM, when you have two categorical Xs and a fully balanced, fully ranked array. I’m beginning to think GLM is the tool to use in real analysis, while Two-Way ANOVA is most practical as a teaching tool to transition from one factor analysis toward multi-factor DOE approaches.

    0
    #186893

    Allattar
    Participant

    The two way ANOVA and general linear model are the same.
    The calculation of the sum of squares, mean squares and F-statistics are the same for both of them. 
    The difference with a general linear model is that it will allow you to enter more factors if you have them, and is not limited to two factors with balanced designs.
    Becuase of this the order of entry of terms into a general linear model can affect the SS calculation on unbalanced designs.  Thus the adjusted SS figure is calculated as well.  This adjusts for the order of terms entered into the GLM.
    However to all intents and purposes a balanced design will give the same results in both analysis.

    0
    #186898

    StuW
    Member

    As pointed out, in the balanced case these analyses are exactly the same and should provide the same results.   What does change is the output provided from the software which is often different depending upon whether the 2-way ANOVA or GLM routines are run.   In the balanced case running the analysis in both ways may give you a particular output that provides a more direct answer to the questions you wish to answer.  For example, prediction of the cell means may be provided in one software output but not in another.

    0
    #186900

    Arap
    Participant

    Thanks for the responses thus far — They are exactly what I was looking for.

    0
Viewing 4 posts - 1 through 4 (of 4 total)

The forum ‘General’ is closed to new topics and replies.