Balanced scales, that is, scales based on items whose content is either negatively or positively polarized, are often used in the hope of measuring a bipolar construct. Research has shown that usually balanced scales do not yield 1-dimensional measurements. This threatens their construct validity. The authors show how to test bipolarity while…

A historicodevelopmental model of acquisition order of words was applied to 175 words comprising the Peabody Picture Vocabulary Test--Revised. A structural equation model demonstrates that the combination of date of entry into English, word length, polysemy, and frequency of use account for a substantial proportion of variance of acquisition…