The Scientific Review of Mental Health Practice

Objective Investigations of Controversial and Unorthodox Claims in Clinical Psychology, Psychiatry, and Social Work

WEAK JUSTIFICATION FOR COMBINING GROUPS

A Reply to Schellenberg (2005)

Author:
Kenneth M. Steele - Appalachian State University

Author Note:
Correspondence concerning this article should be addressed to Kenneth M. Steele, Department of Psychology, Appalachian State University, Boone, NC 28608; e-mail: steelekm@appstate.edu.

Abstract:
Schellenberg (2004) assigned 144 6-year-old children to one of four treatments in a pretest-posttest design. Subjects experienced either keyboard, Kodály voice, drama, or no lessons over an academic year. Schellenberg reported a sig-nificant difference of 2.7 IQ points if the keyboard and voice results were combined and contrasted against the com-bined drama and no-lessons results. Steele (2005) and Black (2005) questioned the justification for this combination and reported that the general pattern was weak and nonsignificant differences in the absence of this particular com-bination. Schellenberg (2005) attempted to justify this combination by appeals to the expense of the project and pub-lic interest in the research question. The result is explained as being due to the school-like nature of the activities. This explanation raises the question of why drama lessons are not school-like and instead were combined with the no-lessons group.


You can read the full text of this article in
The Scientific Review of Mental Health Practice, vol. 4, no. 2 (Fall/Winter 2005-06).
Subscribe now!

  ©2007 Center for Inquiry    | SRMHP Home | About SRMHP | Contact Us |