Skip to main content
SpringerLink
Log in

Picturing repeated measures: Comments on Loftus, Morrison, and others

  • Published:
Behavior Research Methods, Instruments & Computers Aims and scope Submit manuscript

Abstract

Loftus’s (1993b, 1995) recommendation that investigators routinely include plots of appropriate means along with 95% confidence intervals or some other indication of variability has considerable merit, yet we agree with Morrison and Weaver (1995) that such plots can supplement but not supplant the usual reporting of analysis of variance results. Providing them may be easier than Loftus and Masson (1994) indicated, especially when error bars are understood as supplemental descriptive devices. We suggest a general, unified approach that applies to the explication of both between- and within-subjects effects. Variability is estimated separately for each group of scores identified as different by analysis because this serves description better. Raw scores are used for between-subjects effects, scores adjusted for between-subjects variability for within-subjects effects. All computations and figures are easily effected using common spreadsheet programs.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Bakeman, R. (1992).Understanding social science statistics: A spreadsheet approach. Hillsdale, NJ: Erlbaum.

    Google Scholar 

  • Cohen, J. (1968). Multiple regression as a general data-analytic system.Psychological Bulletin,70, 426–443.

    Article  Google Scholar 

  • Cohen, J. (1990). Things I have learned (so far).American Psychologist,45, 1304–1312.

    Article  Google Scholar 

  • Cohen, J., &Cohen, P. (1983).Applied multiple regression/correlation analysis for the behavioral sciences. Hillsdale, NJ: Erlbaum.

    Google Scholar 

  • Edgington, E. S. (1987).Randomization tests. New York: Marcel Dekker.

    Google Scholar 

  • Fisher, R. A. (1970).Statistical methods for research workers (14th ed.). Edinburgh: Oliver & Boyd. (Original work published 1925)

    Google Scholar 

  • Good, P. (1994).Permutation tests: A practical guide to resampling methods for testing hypotheses. New York: Springer-Verlag.

    Book  Google Scholar 

  • Greenhouse, S. W., &Geisser, S. (1959). On methods in the analysis of profile data.Psychometrika,24, 95–112.

    Article  Google Scholar 

  • Hays, W. L. (1963).Statistics. New York: Holt, Rinehart & Winston.

    Google Scholar 

  • Hochberg, Y., &Tamhane, A. C. (1987).Multiple comparison procedures. New York: Wiley.

    Book  Google Scholar 

  • Keppel, G. (1991).Design and analysis: A researcher’s handbook (3rd ed.). Englewood Cliffs, NJ: Prentice-Hall.

    Google Scholar 

  • Kirk, R. E. (1982).Experimental design: Procedures for the behavioral sciences (2nd ed.). Belmont, CA: Brooks/Cole.

    Google Scholar 

  • Loftus, G. R. (1991). On the tyranny of hypothesis testing in the social sciences.Contemporary Psychology,36, 102–105.

    Article  Google Scholar 

  • Loftus, G. R. (1993a). Editorial comment.Memory & Cognition,21, 1–3.

    Article  Google Scholar 

  • Loftus, G. R. (1993b). A picture is worth a thousandp values: On the irrelevance of hypothesis testing in the microcomputer age.Behavior Research Methods, Instruments, & Computers,25, 250–256.

    Article  Google Scholar 

  • Loftus, G. R. (1995). Data analysis as insight: Reply to Morrison and Weaver.Behavior Research Methods, Instruments, & Computers,27, 57–59.

    Article  Google Scholar 

  • Loftus, G. R., &Masson, M. E. J. (1994). Using confidence intervals in within-subject designs.Psychonomic Bulletin & Review,1, 476–490.

    Article  Google Scholar 

  • Morrison, G. R., &Weaver, B. (1995). Exactly how manyp values is a picture worth? A commentary on Loftus’s plot-plus-error-bar approach.Behavior Research Methods, Instruments, & Computers,27, 52–56.

    Article  Google Scholar 

  • Rosnow, R. L., &Rosenthal, R. (1989). Statistical procedures and the justification of knowledge in psychological science.American Psychologist,44, 1276–1284.

    Article  Google Scholar 

  • Tukey, J. W. (1977).Exploratory data analysis. Reading, MA: Addison-Wesley.

    Google Scholar 

  • Turkheimer, M., Bakeman, R., &Adamson, L. B. (1989). Do mothers support and peers inhibit skilled object play in infancy?Infant Behavior & Development,12, 37–44.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Psychology, Georgia State University, 30303, Atlanta, GA, USA

    Roger Bakeman & Duncan Mcarthur

Authors
  1. Roger Bakeman
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Duncan Mcarthur
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Roger Bakeman.

Additional information

We would like to thank C. Chin and C. Davis, graduate students at Georgia State University, whose questions in class first caused us to consider these issues more closely, and D. Borkman Reed for her helpful editorial comments.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bakeman, R., Mcarthur, D. Picturing repeated measures: Comments on Loftus, Morrison, and others. Behavior Research Methods, Instruments, & Computers 28, 584–589 (1996). https://doi.org/10.3758/BF03200546

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.3758/BF03200546

Keywords

Search

Navigation