Research Article

Testing for Main Random Effects in Two-Way Random and Mixed Effects Models: Modifying the Statistic

Table 1

Comparison of achieved type I error rates and power for , , and with tests for the random and mixed effects models.

Random effects model Mixed effects model
Balanced Unbalanced Balanced Unbalanced

Homo.
.054 .220 .111 .247 .049 .167 .092 .198 .065 .047 .112 .099 .063 .045 .109 .086
.053 .229 .123 .265 .069 NA .140 NA .227 .187 .318 .296 .184 .138 .260 .228
.125 .337 .221 .367 .113 NA .201 NA .761 .719 .820 .804 .542 .489 .634 .638
.236 .532 .369 .563 .234 NA .360 NA .975 .963 .982 .982 .888 .863 .920 .917
Hetero.
.045 .150 .089 .182 .015 .230 .042 .303 .070 .056 .106 .100 .062 .935 .107 .952
.045 .160 .088 .199 .021 NA .053 NA .077 .060 .129 .121 .074 NA .124 NA
.114 .273 .190 .316 .047 NA .094 NA .151 .129 .221 .215 .104 NA .152 NA
.195 .430 .318 .467 .117 NA .215 NA .270 .235 .353 .341 .131 NA .189 NA