Comments on an article by J. Allison et al (see record 1980-27214-001). Conservation theory in either its 1- or 2-parameter form predicts a linear relation with negative slope between measures of the instrumental and contingent response. Empirical results from ratio schedule experiments conform to the linear prediction over a limited range, but results from experiments with VI schedules are not consistent with the linear model. (13 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.