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AW: [OB-LIST] Low alpha scores of Big 5 TIPI scale

  • 1.  AW: [OB-LIST] Low alpha scores of Big 5 TIPI scale

    Posted 03-24-2010 03:57

    Hi folks,

    in most cases in which a scale has a low alpha the reason is simply that the items in the scale measure

    different things. Thus, the alpha indicates not only reliability but is also a function of the correlation among the respective latent variables.

     

    Remember that alpha as a reliability measure requires essential tau-equivalance  - that is all items measure one latent variable and have equal factor loadings.

     

    My add-on ref list:

     

    Graham, J. M. (2006). Congeneric and (essentially) tau-equivalent estimates of score reliability. Educational and Psychological Measurement, 66(6), 930-944.

    Gerbing, D. W., & Anderson, J. C. (1988). An updated paradigm for scale development incorporating unidimensionality and its assessment. Journal of Marketing Research, 25, 186-1982.

     

    Huysamen, G. K. (2006). Coefficient alpha: Unnecessarily ambiguous; unduly ubiquitous. South-African Journal of Industrial Psychology, 32(4), 34-40.

     

    Sijtsma, K. (2009). On the use, the misuse, and the very limited usefulness of Cronbach's alpha. Psychometrika, 74(1), 107-120.

     

    Best,

    Holger

     

     

    Von: Organizational Behavior Division Listserv [mailto:OB@AOMLISTS.PACE.EDU] Im Auftrag von Mark Ehrhart
    Gesendet: Mittwoch, 24. März 2010 01:59
    An: OB@AOMLISTS.PACE.EDU
    Betreff: Re: [OB-LIST] Low alpha scores of Big 5 TIPI scale

     

    Stefan,

    My colleagues and I recently published an article in PAID evaluating the TIPI relative to a 50-item measure from the International Personality Item Pool (IPIP).  The results on the whole were actually more positive than we had expected, although the alphas were generally low.  We didn't have the space to explore the issue in much depth, but we did briefly touch on it at the end of the the Discussion section.  Here's the citation:

    Ehrhart, M. G., Ehrhart, K. H., Roesch, S. C., Chung-Herrera, B. G., Nadler, K., & Bradshaw, K. (2009).  Testing the latent factor structure and construct validity of the Ten-Item Personality Inventory.  Personality and Individual Differences, 47, 900-905.

    Regards,

    Mark

    On Tue, Mar 23, 2010 at 5:33 AM, Stefan Volk <stefan.volk@uni-tuebingen.de> wrote:

    Dear all,

    we used the Gosling et al. (2003) 10-item personality inventory (TIPI) and obtained low Cronbach's alpha scores. Sam Gosling provides an explanation on his website indicating that alphas are misleading when calculated on scales with small numbers of items. I was wondering if someone could provide me with or point me to some more arguments for reviewers apart from the explanation given by Sam, in the ideal case something that has been published. I see once in a while that authors do not report alphas if they use two-item scales. What is the theoretical argument of not reporting alphas, if scales consist of only two items?

    Many thanks in advance,
    Stefan 

    -- 
    Dr. Stefan Volk
     
    Tübingen University 
    Department of International Business
    Melanchthonstr. 30
    72074 Tübingen
    Germany
     
    Phone +49 707 129 74046
     




    --
    Mark Ehrhart, Ph.D.
    Associate Professor
    Department of Psychology
    San Diego State University
    5500 Campanile Drive
    San Diego, CA  92182-4611
    619-594-4439 (phone)
    619-594-1332 (fax)
    mehrhart@sunstroke.sdsu.edu