International Journal of Research in Marketing
, 11 (1994), 233-248
Replications and Extensions in Marketing –
Rarely Published But Quite Contrary
Drake University, Des Moines, IA 50311, USA
J. Scott Armstrong
The Wharton School, University of Pennsylvania, Philadelphia, PA 19104, USA
Replication is rare in marketing. Of 1,120 papers sampled from three major marketing
journals, none were replications. Only 1.8% of the papers were extensions, and they
consumed 1.1% of the journal space. On average, these extensions appeared seven
years after the original study. The publication rate for such works has been decreasing
since the 1970s. Published extensions typically produced results that conflicted with
the original studies; of the 20 extensions published, 12 conflicted with the earlier
results, and only 3 provided full confirmation. Published replications do not attract as
many citations after publication as do the original studies, even when the results fail
to support the original studies.
"Replicability is almost universally accepted as the most important
criterion of genuine scientific knowledge.
Rosenthal and Rosnow, 1984, p. 9
"Replicability . . . is the Supreme Court of the scientific system."
Collins, 1985, p. 19
As suggested by the above quotations, replication is held in high regard by some
scientists. Other things being equal, the failure to obtain similar findings in a replication indicates
the need for further work in the area. A successful replication, on the other hand, promotes
confidence in the reliability of the results, and suggests the need to study whether the findings
can be generalized to different populations, products, geographical areas, and so on. Replications
The authors thank Richard Bagozzi, Gregory Boller, Stephen Brown, Gilbert Churchill, Andrew Ehrenberg, James
Engel, Anthony Greenwald, Robert Mittelstaedt, Leonard Reid, Robert Rosenthal. Daniel Vetter, the editor, and
three anonymous reviewers for comments on earlier versions of this paper. Daniel Vetter also assisted with the
classification of the replications and extensions. Editorial assistance was provided by Jennifer Armstrong and
Phan Lam. Any remaining errors are our responsibility.