Investigating a computerised test of the Stroop effect extended by inclusion of a third, more difficult task

A validation study of a computerised test recently developed involving the Stroop effect, extended here by inclusion of a third, more difficult test series, is presented. Three groups of men belonging to the Swedish armed forces and adjudged to differ in their qualifications (20, 32, and 19 men of levels 1, 2, and 3, respectively) and a fourth group of 18 men convicted of serious crimes of violence were given this test, termed the Stress Strategy Test. Discriminant analysis of the test's 12 variables (four for each of the three test series) yielded a discriminant power of 65% for the total group, highest for the level 1 group (80%) and for the nonmilitary group (72%), results substantially better than obtained for the original version of the test with use of similar subject groups.