# A formula for Type III sums of squares

@article{Lamotte2019AFF, title={A formula for Type III sums of squares}, author={Lynn Roy Lamotte}, journal={Communications in Statistics - Theory and Methods}, year={2019} }

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…

## One Citation

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