Using R and psych for personality and psychological research

User manual and help files

  1. The psych user manual (pdf)
  2. The individual help files for the psych package in html


  1. introduction (pdf) to the psych package
  2. An Overview of psychometric functions (pdf) in the psych package
  3. Using psych as a front end for sem (pdf) to the psych package

How to

  1. Install R and psych on your computer.
  2. Use psych in order to find omega
  3. Score a set of items to use psych in order to find composite scores
  4. Factor analyze a data set

Short Course lecture notes

These are clickable pdf lecture notes

  1. American Psychological Associaton July, 2017, (notes)
  2. Society for Applied Multivariate Research April, 2017, (notes)
  3. Association for Psychological Science May, 2017, (notes)
  4. World Conference on Personality, March, 2013 (notes)
  5. Association for Research in Personality, June, 2011 (notes)

Supplementary readings

Gathered from around the web

  • Resources for R (from Sara Weston)
  • Sara Weston and Debbie Yee (2017) Why you should become a UseR: A brief introduction R
  • Source code and development version

  • Source Code (zip file)
  • Development Version for PCs or Macs at the the PMC repository:
    install.packages("psych", repos="", type="source" )

    R is a very powerful open source system for statistical computation and graphics. It consists of a language plus a run-time environment with graphics, a debugger, access to certain system functions, and the ability to run programs stored in script files. Base R is a foundation upon which more than 17,000 "packages" have been built. It is the use of these packages that makes R such a powerful tool for research.

    The psych package has been developed at the Personality, Motivation and Cognition laboratory in the Department of Psychology at Northwestern University since 2005 to include functions most useful for personality, psychometric, and psychological research. The package is also meant to supplement a text on Psychometric Theory, a draft of which is available on line.

    The development of the psych package was done in conjunction with the development of the Synthetic Aperture Personality Assessment (SAPA) project and is a core part of the International Cognitive Ability Resource (ICAR) project. The SAPA project includes a personality test that uses a massively missing at random strategy to measure dimensions of temperament, ability, and interests.

    To start using the psych package, it is, of course, necessary to install R and the psych package. Then one should read the Introduction and overview for psychometrics vignettes about psych and work through those examples. There are several short courses demonstrating R as used for psychology. These are large files. Alternatively, the R guide might provide a good start.

    Reporting bugs in the psych package

  • Although I try to make the psych package easy to use and bug free, this is impossible. If you discover a bug, please report it revelle @ .
  • Please report the version number of R and of psych, and a minimal example of the problem. If possible, include an Rds file containing the offending data and the code you used when you found the bug.
  • If you have problems understanding how to use a function, please first refer to the help file for that function, look at the examples, and read the notes. Reading the vignettes is also useful.