Alpha Inflation? The Impact of Eliminating Scale Items on Cronbach's Alpha

Abstract

In this paper, we study the effect of the elimination of items from a scale so that only those items that correlate highly are chosen. Using a simulation, we estimate the impact on Cronbach's alpha as a function of the total number of items in a scale, the number of items chosen, the true correlation among the items, and the sample size. The results suggest that a substantial effect can exist. Not surprisingly, the effect is larger when sample sizes are smaller, when a smaller fraction of the original items is retained, and when there is greater variation in the true item-total correlations of the measures.

Cite this work

No public copy is stored for this record, so only the metadata is cited.

Stored only when both papers are in the corpus — 127 citations exist upstream.

Papers that cite the same references — the relational fallback while embeddings are still backfilling.