The PSYCHLAB programming system: A tool for developing experimental control programs

The PSYCHLAB system is designed to facilitate the task of writing experimental control programs. The system consists of two major components: (1) a collection of procedures and functions to facilitate presenting stimuli, collecting responses, and measuring response times and (2) a high-level language (LAB-TALK) designed to organize and sequence events in experiments. The PSYCHLAB system is formally an interpreter that will interpret programs written in LAB-TALK. The interpreter is customized to perform the detailed functions of each trial in an experiment. The occurrence of these trials is controlled by the LAB-TALK program. Thus, once a particular experimental paradigm has been represented in a customized version of the interpreter, many different experiments in that paradigm can be programmed by variations in the LAB-TALK program.     

FUNCTIONAL ASSESSMENT,CURRICULAR REVISION,AND SEVERE BEHAVIOR PROBLEMS

An adolescent female with multiple handicaps and a long history of severely disruptive behavior participated in a functional assessment linked directly to specific revisions in her school curriculum. During Phase 1, reversal designs were used to test hypotheses pertaining to antecedent and auricular influences on problem behavior. During Phase 2, a multiple baseline across afternoon and morning time periods demonstrated that the auricular revisions were effective in eliminating severely disruptive behavior and increasing on-task responding. Data also showed that inappropriate “psychotic” speech was reduced and appropriate social interactions were increased. Follow-up results showed that the changes were maintained throughout the school year. Questionnaire data provided social validation of the procedures and outcomes. The findings are discussed in relation to their implications for functional assessment, individualized curricula, and positive programming for students with disabilities and serious behavior problems.     

The equivalence of three statistical packages for performing hierarchical cluster analysis

Three different software programs which contain hierarchical agglomerative cluster analysis procedures were shown to generate different solutions on the same data set using apparently the same options. The basis for the differences in the solutions was the formulae used to calculate Euclidean distance. Users of statistical software were warned of terminological confusion concerning cluster analysis.This research was supported by a National Science Foundation grant (DCR#74-20007) entitled A Consumer Report on Cluster Analysis Software. I wish to thank the authors of the three programs for their helpful comments on the paper.