How sensitive are handedness prevalence figures to differences in questionnaire classification procedures?

Questionnaire data from 572 subjects show that the proportion of right-handers to nonright-handers varies greatly (from 1:100 to 92:8) as a function of questionnaire length, graded or forced response to items, and cut-off criteria. For this reason, the right-handed/nonright-hander dichotomy is singularly unsuited as a basis for classification when handedness is to be related to some other neuropsychological factor as an independent variable. This is especially the case when very strict cut-off criteria are used to define right-handedness (e.g., only those individuals who prefer the right hand for all activities listed).     

The impact of television,print, and audio on children's recall of the news.

Recent research has shown that children remember more from television news than from print news, a finding that has been explained by the extra mnemonic support offered by redundant television pictures (the dual‐coding hypothesis). The present study was designed to examine three alternative explanations, which attribute children's superior recall of television news to (a) underutilization of the print medium, (b) a recall advantage of listening compared with reading, and imperfect reading ability. A sample of 192 fourth and sixth graders was presented with children's news stories, either in (a) their original television form, (b) a bare print version, a print version supplemented with photo material or in (d) an audio version. Results indicated that the television presentation was remembered better than any of the other three versions. The results of the study were consistent with the dual‐coding hypothesis, whereas no support was found for the alternative explanations tested in the study.