John,

I would look at a couple articles by:

Hulin, C. (2001). Can a reliability coefficient be too high? Journal of Consumer Psychology, 10 (1, 2), 56.

Netemeyer, R. (2001). Can a reliability coefficient be too high? Journal of Consumer Psychology, 10 (1, 2), 56-57.

These basically state the the inter-item correlation needs to be evaluated against the purpose of the scale, in academia .80 is usually low, in consumer based scales I have used ones with an Alpha as low as .65.

The formula used to compute Alpha suggests that as the number of items in a scale increase, the correlation will increase and therefore will produce a large Alpha. This can lead to items in a scale being redundant and not just reliable.

Colin M. Valdiserri Associate Consumer Scientist The Calphalon Group (419) 662-2378 - Office (419) 661-0223 - Fax colin.valdiserri@calphalon.com

-----Original Message----- From: John Antonakis [mailto:John.Antonakis@hec.unil.ch] Sent: Wednesday, September 24, 2003 5:25 PM To: SPSSX-L@LISTSERV.UGA.EDU Subject: Item-total correlation

Hi:

Does anyone have a cite regarding what the minimum necessary value for an item-total correlation should be, which would demonstrate that the item is strongly related to the items consituting a particular scale? What would/should that value be?

Thanks, John.

********************************************************************* John Antonakis, Ph.D. Assistant Professor Department of Management, HEC University of Lausanne 503-BFSH-1 CH-1015 Lausanne-Dorigny Switzerland

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