A Formula for Type III Sums of Squares
Abstract
Type III methods were introduced by SAS to address difficulties in dummy-variable models for effects of multiple factors and covariates. They are widely used in practice; they are the default method in several statistical computing packages. Type III sums of squares (SSs) are defined by a set of instructions; an explicit mathematical formulation does not seem to exist. An explicit formulation is derived in this paper. It is used to illustrate Type III SSs and their properties in the two-factor ANOVA model.
- Publication:
-
arXiv e-prints
- Pub Date:
- March 2018
- arXiv:
- arXiv:1804.00545
- Bibcode:
- 2018arXiv180400545L
- Keywords:
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- Statistics - Methodology;
- 62J05;
- 62J10;
- 62F03
- E-Print:
- arXiv admin note: text overlap with arXiv:1708.06483