A Study of the Properties of the Item Count Technique

The item count technique is an indirect questioning techniquethat is used to estimate the proportion of people who have engagedin stigmatizing behavior. This technique is expected to yielda more appropriate estimate than the ordinary direct questioningtechnique because it requests respondents to indicate, basedon a list of several items, simply the number of items thatare applicable to them, including the target key item. An experimentalweb survey was conducted in an attempt to compare the directquestioning technique and the item count technique. Comparedwith the direct questioning technique, the item count techniqueyielded higher estimates of the proportion of shoplifters bynearly 10 percentage points, whereas the difference betweenthe estimates using these two techniques was mostly insignificantwith respect to innocuous blood donation. The survey resultssuggest that in the item count technique respondents tend toreport fewer total behaviors compared to the direct questioncase. This tendency is more pronounced in the case of longeritem lists. Three domain estimators for the item count techniquewere compared, and the cross-based method appeared to be themost appropriate method. Large differences in domain estimatesfor shoplifting between the item count and direct questioningtechniques were found among female respondents, middle-agedrespondents, respondents living in urban areas, and highly-educatedrespondents.