A Comparative Analysis of the Performance of Alternative Measures of Exposure

摘要

This paper compares eight approaches to measurement of exposure to cancer information in the mass media: general media exposure, exposure to health media, attention to health topics, quantity of health information, general and specific cancer exposure assessed by closed- and by open-ended questions. After demographic controls, the strongest predictor of cancer knowledge was the open-ended general measure (9.8percent additional variance), then open-ended and closed-ended measures about diet and exercise (each 6.7percent), attention to health topics (6.2percent), quantity of health information (4.1percent), and health media exposure (3.7percent). General media exposure was not associated. However, other validity criteria lead to different conclusions: attention measures may confound motivation with exposure, and there may be upward bias in using knowledge to validate open-ended exposure measures; considering face validity, survey costs and respondent burden as well as criterion validity, we propose that the closed-ended specific questions may be most useful.