The Proximity Effect: The Role of Interitem Distance on Reverse-Item Bias

On the basis of cognitive interviews and drawing on the belief-sampling model, we introduce the proximity effect model. The model explains the correlation between two items as a function of their conceptual relationship (nonreversed same-construct items, reversed same-construct items, unrelated items) and their proximity in the questionnaire. In a quantitative study using primary data (N = 3,114), the (positive) correlation between a nonreversed item pair decreases with increasing interitem distance. In contrast, the (negative) correlation between reversed item pairs decreases (i.e., become stronger) with increasing interitem distance. This is related to the way respondents tend to minimize retrieval of additional information when answering nearby nonreversed items and maximize retrieval of new and different information when answering nearby reversed items. Using two simulated correlation matrices that represent common measurement situations, we assess the impact of the proximity effect on factor structure and reliability. The resultant key recommendations pertain to the use of reversed items that are dispersed throughout the questionnaire and the use of a confirmatory factor analysis model specification including a response style factor.