Abstract
Objectives The Implicit Association Test (IAT) and the Single-Category IAT (SC-IAT) are two frequently used measures of implicit attitudes. Nonetheless, the test-retest reliability of these measures has not been investigated. The aim of this study was to examine the test-retest reliability of a physical activity versus sedentary behavior IAT, a physical activity SC-IAT, and a sedentary behavior SC-IAT. Method A total of 111 older adults living with chronic diseases were recruited. They either completed a physical activity versus sedentary behavior IAT (N = 54) or two independent SC-IATs of physical activity and sedentary behavior (N = 57). These tests were administered twice in a one-hour interval. Three scores were computed for each test (D-Score, DW-Score, IP-Score). Both absolute and relative test-retest reliability was computed. Results Regarding absolute reliability, the tests were comparable regardless of the scoring algorithm (Coefficients of Repeatability ranged from 1.27 for the two SC-IATs with the D-Score, to 1.36 for the IAT with the D-Score and DW-Score). Regarding relative test-retest reliability, the IAT systematically showed better reliability than the two SC-IATs. The DW-Score systematically exhibited better reliability compared to other scores (Intraclass Correlation Coefficient ranged from 0.20 for the sedentary behavior SC-IAT with the D-Score to 0.78 for the IAT with the DW-Score). Conclusion Adequate test-retest reliability for the IAT was supported independently from the scoring algorithms. Test-retest reliability for the two independent SC-IATs was not supported in this study. The IAT is more sensitive to change than the SC-IATs, which needs to be accounted for in future research on physical activity and sedentary behavior implicit attitudes.