Test-Retest Reliability and Concurrent Validity of the Expanded Skills Confidence Inventory

This study examined the test-retest reliability and the concurrent validity of the 17-scale Expanded Skills Confidence Inventory in samples of 321 and 175 college students. Retest values over a 3-week interval ranged from .77 to .89, with a median of .85. Using Brown and Gore’s C-index, evidence for the concurrent validity of confidence score patterns relative to college major choice was found. Specifically, the values of C describing the congruence of the three-letter Holland code derived from the 17 confidence scores with the Holland code of college major choice were significantly higher than the theoretical mean and were comparable in size to values found in samples of employed adults. Higher congruence scores were found among students majoring in enterprising and secondarily, investigative areas.