Computer Programs from the PMC Lab

Older programs -- for Mac OS 9.2 and classic mode on Mac 10.xx

A number of computer programs for multivariate-experimental psychology have been developed in the Personality, Motivation, and Cognition Laboratory at Northwestern University. These programs have been written to facilitate data analysis, scale identification, and scale construction (the ICLUST-VSS-Alpha package) and well as to collect mood scores on-line, measure reaction time and accuracy to simple and complex stimuli.

These programs are available as stand alone application programs for Macintosh computers. Source code in Lightspeed Pascal is also available. Publications that describe the algorithms or applications of these programs are listed.

ALPHA-VSS-ICLUST is a general purpose program for scale construction, hierarchical cluster analysis, and applying the Very Simple criterion. Some simple data manipulation options are also available. Hierarchical clustering is done using the alpha and beta criteria of cluster goodness. (Beta is an estimate of the worst split half reliability of a cluster and thus is an estimate of the general factor saturation of a test). For the program, the users guide, and some sample files in a self extracting folder for a Mac.

Revelle, W., & Rocklin, T. (1979). Very Simple Structure: an alternative procedure for estimating the optimal number of interpretable factors. Multivariate Behavioral Research, 14, 403-414.

Revelle, W. (1979). Hierarchical cluster analysis and the internal structure of tests. Multivariate Behavioral Research, 14, 57-74.

PMC-RT is a set of simple and choice reaction time procedures allowing for the measurement of rt as well as the assessment of changes in rt over time.

Revelle, W. (1993). Individual differences in personality and motivation: Non-cognitive determinants of cognitive performance. In A. Baddeley & L. Weiskrantz (Eds.),Attention: Selection, awareness and control: A tribute to Donald Broadbent (pp. 346-373). Oxford: Oxford University Press.

True false or multiple choice geometric analogies that vary in the number of elements and transformations applied per element. Accuracy and rt measures are taken. Elements may vary from 1-4 and transformations from 0-4.

Revelle, W. (1989) Personality, Motivation, and Cognitive Performance. P. Ackerman, R., and R. Cudeck (Eds.): Learning and Individual Differences: Abilities, Motivation, and Methodology. Erlbaum. (pp. 297-341).

Onken, J., & Revelle, W. (1984) ANATEST: a program to generate geometric analogy problems varying in number of elements and number of transformations. Behavior research methods instruments and computers. 16, 333-334.

Working-Memory .
Working memory for 2-10 digits following the true false verification of arithmetic problems. Speed and accuracy of the digit verification are reported, as are strict and lax memory scores.

A set of Pascal units that have been developed to allow for standardized programing of psychology experiments and data analysis.

Newer programs -- written in R

Taking advantage of the very powerful statistical and data manipulation language R, I have developed and am developing programs (e.g., VSS, omega) to extend the capabilities of the old Mac programs.

See my userguide to R, as well as the various programs being developed as part of the "psych" package.

Finds the Very Simple Structure criterion for the optimal number of factors.