Abstract
The concepts of internal and external validity, developed by Norman Campbell, are widely used to structure methodological thinking about social research. This article points to ambiguities in the interpretation of those terms, both as regards the relationships they refer to as well as the sort of object that is held to be capable of internal and external validity. In addition, it is suggested that the distinction between these types of validity is fundamentally misleading because it reflects a failure to distinguish relations between events and relations between variables. It also rests on the false assumption that we can separate the discovery of causal relationships from the question of whether these apply to other cases than the ones studied. In the final section, an alternative conceptualisation of validity is sketched, one that avoids the problems identified.
Similar content being viewed by others
References
BrachtG.H. & G.V.Glass (1968). “The external validity of experiments”,American Educational Research Journal 5: 437–74.
CampbellD. (1957). “Factors relevant to the validity of experiments in social settings”,Psychological Bulletin 54(4): 297–312.
CampbellD. & J.Stanley (1963). “Experimental and quasi-experimental designs for research on teaching”, in N. L.Gage (ed.),Handbook of Research on Teaching, Chicago, Rand Mcnally.
CookT. & D.Campbell (1979).Quasi-Experimentation, Chicago, Rand McNally.
DenzinN.K. (1978).The Research Act, New York. McGraw Hill.
DominowskiR. (1980)Research Methods, Englewood Cliffs, Prentice Hall.
KruglanskiA. & M.Kroy (1976). “Outcome validity in experimental research: a re-conceptualization”,Representative Research in Social Psychology 7: 166–78.
MillerA. G. (1986).The Obedience Experiments: a case study of controversy in Social Science, New York, Praeger.
SmithH. W. (1975).Strategies of Social Research, Englewood Cliffs, Prentice Hall.
StarS.A. & H.M.Hughes (1949–50) “Report on an educational campaign: the Cincinnati plan for the United Nations”,American Journal of Sociology 55: 389.
Author information
Authors and Affiliations
Additional information
Thanks go to John Scarth and John Bynner for comments on an earlier draft of this paper.
Rights and permissions
About this article
Cite this article
Hammersley, M. A note on campbell's distinction between internal and external validity. Qual Quant 25, 381–387 (1991). https://doi.org/10.1007/BF02484586
Issue Date:
DOI: https://doi.org/10.1007/BF02484586