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Topic 8

Section outline

  • Topic 8

    Topics:
    • Test for "lack of fit".
    • Two-way analysis of variance.
    • ANOVA in the unbalanced case.
    • Analysis of Covariance.
    Read: Montgomery, Sec. 10.8, 5.1, 5.2, 5.3, 15.2. We will also do analysis of covariance, but you don't need to read Sec. 15.3, just read the introduction to this section - the formulas are too complicated, and it is much easier to use R.

    Location: Niels Jernes Vej 14, room 3-119

    Remarks:

    • Concerning explanatory variables, notice that a quantitative (continuous) variable gives one degree of freedom, whereas for a qualitative variable (factor) the number of degrees of freedom is one less than the number of levels.
    • In testing "lack of fit", analysis of variance and regression analysis are combined. In the former, the explanatory variable is considered qualitative (a factor) with degrees of freedom one less than the number of levels. In the latter, the explanatory variable is considered quantitative (continuous) with only one degree of freedom.
    • Remember to test interaction before main effects. Montgomery seems to suggest the other (illogical) order.

    Handin 2: Handin 2 is now available.

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