Are we over- or under-projecting and how much? decisive issues of methodological validity and item type
Article first published online: 9 JAN 2004
Copyright © 2004 John Wiley & Sons, Ltd.
European Journal of Social Psychology
Volume 34, Issue 1, pages 55–68, January/February 2004
How to Cite
Jones, P. E. (2004), Are we over- or under-projecting and how much? decisive issues of methodological validity and item type. Eur. J. Soc. Psychol., 34: 55–68. doi: 10.1002/ejsp.187
- Issue published online: 9 JAN 2004
- Article first published online: 9 JAN 2004
- Manuscript Accepted: 31 JUL 2003
- Manuscript Received: 21 SEP 2002
Pertinent to the question of projective error, two methodological factors that threaten the descriptive validity of projection measures are considered in conjunction with the effects of item type (abilities vs. opinions). Study 1 examined the effect of experimental paradigm. Compared to the assumed similarity method, projection indices from the consensus method were significantly lower resulting in reduced accuracy. Study 2 focused on measurement sequence effects. Measuring group estimates before self-ratings produced higher, but more valid projection indices. The ability-opinion distinction was a factor common to both studies. The effect of item type on accuracy was mediated by projection: accuracy was greater on opinions because projection was stronger. For both item types, measures of projective error implied under-projection. Whilst the degree of error rests ultimately on paradigm validity, the heuristic value of projection should remain unrealised. Copyright © 2004 John Wiley & Sons, Ltd.