takahiro tsuchiya is an associate professor at The Institute of Statistical Mathematics, 4–6–7, Minami-Azabu, Minato-ku, Tokyo, 106-8569, Japan. yoko hirai is an associate professor of psychology at Tokyo Metropolitan University, 1-1, Minami-Osawa, Hachioji-Shi, Tokyo, 192-0397, Japan. shigeru ono is an assistant manager at Synovate K.K. Toranomon-Marine Bldg., 3-18-19, Toranomon, Minato-ku, Tokyo, 105-0001, Japan.
The item count technique is an indirect questioning technique that is used to estimate the proportion of people who have engaged in stigmatizing behavior. This technique is expected to yield a more appropriate estimate than the ordinary direct questioning technique because it requests respondents to indicate, based on a list of several items, simply the number of items that are applicable to them, including the target key item. An experimental web survey was conducted in an attempt to compare the direct questioning technique and the item count technique. Compared with the direct questioning technique, the item count technique yielded higher estimates of the proportion of shoplifters by nearly 10 percentage points, whereas the difference between the estimates using these two techniques was mostly insignificant with respect to innocuous blood donation. The survey results suggest that in the item count technique respondents tend to report fewer total behaviors compared to the direct question case. This tendency is more pronounced in the case of longer item lists. Three domain estimators for the item count technique were compared, and the cross-based method appeared to be the most appropriate method. Large differences in domain estimates for shoplifting between the item count and direct questioning techniques were found among female respondents, middle-aged respondents, respondents living in urban areas, and highly-educated respondents.