Biasing of Hyperkinetic Behavior Ratings by Diagnostic Reports: Effects of Observer Training and Assessment Method

Videotapes of two preschool children were observed by 24 raters. Raters were given diagnostic reports suggesting hyperkinesis for one of the children but not for the other. Twelve raters used a rating scale to assess hyperkinesis, while the remainder used a time-sampling method. Within each of these groups, half of the raters received training on the instrument they used. The results indicate that training had the effect of reducing the biasing effect of the diagnostic label when the rating scale was employed. No biasing effect was noted for the time-sampling results. Discussion centered on the use of observational training and time sampling as methods of obtaining minimally biased data on labeled populations.