For many years, writing skills were treated as the ugly stepsister of reading skills. Tests of “verbal aptitude” and “verbal ability” comprised assessments of vocabulary, reading comprehension, and verbal reasoning. Writing was nowhere to be found. Even achievement tests of “English composition” created by the College Board often had no actual writing whatsoever. Although Louis
Thurstone distinguished between verbal comprehension and verbal fluency in his early theory of primary mental abilities, the former has been widely measured, the latter only rarely. And when the latter was measured, it was typically by tests requiring writing at a basic level, such as writing down as many words beginning with a certain letter as an examinee could think of in a specific time period.