Behavior Research Methods, Instruments, & Computers

, Volume 32, Issue 3, pp 389–395 | Cite as

Determining the number of factors to retain: Q windows-based FORTRAN-IMSL program for parallel analysis

  • Jennifer D. KaufmanEmail author
  • William P. Dunlap


Parallel analysis (PA; Horn, 1965) is a technique for determining the number of factors to retain in exploratory factor analysis that has been shown to be superior to more widely known methods (Zwick & Velicer, 1986). Despite its merits, PA is not widely used in the psychological literature, probably because the method is unfamiliar and because modern, Windows-compatible software to perform PA is unavailable. We provide a FORTRAN-IMSL program for PA that runs on a PC under Windows; it is interactive and designed to suit the range of problems encountered in most psychological research. Furthermore, we provide sample output from the PA program in the form of tabled values that can be used to verify the program operation; or, they can be used either directly or with interpolation to meet specific needs of the researcher.


Exploratory Factor Analysis Parallel Analysis Scree Plot Nitr Multivariate Behavioral Research 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Psychonomic Society, Inc. 2000

Authors and Affiliations

  1. 1.Department of PsychologyTulane UniversityNew Orleans

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