| Abstract: | The accuracy of short-cut estimates of standard deviation was investigated for distributions of raw scores on classroom tests and computer generated samples. Estimates proposed by Mason and Odeh, Jenkins, Diederich, Ebel, and Davenport were compared for relative accuracy in three studies. The loss in accuracy due to short-cut methods versus the conventional statistic ranged from 0 to 7,8%. Based on the findings of these studies, it is recommended that a shortcut method for computing standard deviations he included in courses where the conventional formula is taught. |
