English

A Formula for Type III Sums of Squares

Methodology 2018-04-03 v1

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.

Keywords

Cite

@article{arxiv.1804.00545,
  title  = {A Formula for Type III Sums of Squares},
  author = {Lynn Roy LaMotte},
  journal= {arXiv preprint arXiv:1804.00545},
  year   = {2018}
}

Comments

arXiv admin note: text overlap with arXiv:1708.06483