Some effects of response-correlated increases in reinforcer magnitude on human behavior

After training under short or long fixed-interval schedules, humans responded under a modified fixed-interval schedule in which magnitude of reinforcement (X or 2X) was minimally correlated with response frequency. Response frequencies that equaled or exceeded a minimum response criterion were followed by the larger reinforcer at the end of the interval; otherwise, the smaller reinforcer was delivered. The modified schedule alternated with the baseline schedule across conditions. In a control condition, the reinforcer magnitudes produced by control subjects were yoked to those of experimental subjects. Experimental subjects, but not control subjects, showed increased responding. In addition to the baseline and modified fixed-interval schedules used in Experiment 1, subjects in Experiment 2 also responded under a second modified fixed-interval contingency in which increases in reinforcer magnitude were more highly correlated with response frequency. Experimental subjects, but not control subjects, showed increased responding under both procedures. Direct comparison of these two procedures showed that the high-correlation procedure produced greater increases in responding than did the low-correlation procedure.     

Human Performance Under Progressive Ratio Contingencies

The Psychological Record - Ten human subjects experienced a progressive ratio schedule under three different reinforcement conditions; (a) 20-point increments on a computer screen for each ratio...     

Use of local norms to improve high-point code-type concordance of two short forms of the MMPI

Criticisms of short forms of the MMPI have been based on claims of unsatisfactory high-point code-type concordance rates. The use of local norms has been suggested as a possible solution for these low concordance rates. In this study local norms for three client populations were developed for the MMPI-168 and Faschingbauer's abbreviated MMPI. These local norms did not significantly increase high-point code-type concordance. Possible explanations for these findings are discussed and suggestions for future research offered.     

Determination of the number of independent parameters of a score matrix from the examination of rank orders

Two ordinal consequences are drawn from the linear multiple-factor analysis model. First, the numberR(s, d) of distinct ways in whichs subjects can be ranked by linear functions ofd factors is limited by the recursive expressionR(s, d)=R(s?1,d)+(s?1)R(s?1,d?1). Second, every setS ofd+2 subjects can be separated into two subsetsS* andS ? S* such that no linear function ofd variables can rank allS* over allS ? S*, and vice versa. When these results are applied to the hypothetical data of Thurstone's “box problem,” three independent parameters are found. Relations to Thurstone's suggestion for a non-correlational factor analysis are discussed.