A note on time out from avoidance with the chimpanzee

Fixed-interval responding which produced time out from shock avoidance schedules was established in a chimpanzee. Two widely differing discriminated avoidance schedules were employed in a multiple schedule arrangement. Differences in fixed interval rate were found to be related both to the schedule from which the subject was escaping and to the amount of training.     

A note on the minres method

This paper discusses the advantages and problems related to factor analysis by minimizing residuals (minres). It is shown that this method fails if the starting point of iterations is not well chosen. A suitable starting point is suggested.     

A note on the Neyman-Johnson technique

A statistical problem which frequently arises in educational and psychological experimentation is that of testing the significance of the difference of the mean scores of two groups on some criterion variable, where the differential effects of one or more variables which are correlated with the criterion must be statistically eliminated. The usual analytical technique for this type of problem is the analysis of covariance (9). The Neyman-Johnson technique (7) provides another, and substantially different, approach. A computational procedure is suggested here which utilizes the advantages of both techniques without an undue increase in computational labor. In addition, the Neyman-Johnson technique is generalized to the case ofn predictor variables. Its application has heretofore been limited to a maximum of three predictor variables.This paper was written while the author was a Psychometric Fellow of the Educational Testing Service, Princeton, New Jersey.