ERIC Number: ED099306
Record Type: RIE
Publication Date: 1974-Sep-30
Reference Count: 0
Consistency and Stability of Interaction Effects from Classroom to Classroom: Pilot Studies.
Cronbach, Lee J.
This interim report is concerned with the analysis of educational experiments and quasiexperiments where alternative teaching methods are applied to intact classes or where alternative programs are set up in samples of schools or communities. Generally, such studies have used the class, the school, or the community as the unit of sampling with the consequence that investigators have based the number of degrees of freedom in their statistical calculations on the number of classes. However, the author believes that a further distinction must be made: that is, between effects that operate at the class level and effects that operate within the class. The variance in an outcome measure can be divided into between-class and within-class components. The between-class variance can in turn be divided into variance predicted from the aptitude level of the class and a residual. The within-class variance can be subdivided into the effect predicted from the within-class regression equation and a residual. The regression equation with each single class can then be computed and the residual reduced still further. The author has developed methods for completing such analysis and applies them to previous studies to show the effect of such analysis on the outcomes of studies. (HMD)
Publication Type: Reports - Research
Education Level: N/A
Authoring Institution: Spencer Foundation, Chicago, IL.