Elementary school-age children's capacity to choose positive diagnostic and negative diagnostic tests

Two experiments involving 72 elementary school-age children (mean age = 10 years, 3 months, range = 9,411,S) and 72 adults compared the ability of participants to choose positive and negative diagnostic tests over positive and negative nondiagnostic tests. Both experiments employed novel test materials, which resolved any issues regarding the effects of context on test strategy employment. In Experiment 1, both children and adults were significantly more likely to prefer positive diagnostic tests over positive nondiagnostic tests; however, only adults demonstrated a significant preference for negative diagnostic tests over positive nondiagnostic ones. In Experiment 2, both children and adults were more likely to choose negative diagnostic tests over negative nondiagnostic tests, demonstrating that despite a strong positive test bias, children could reason diagnostically in selecting among negative tests in cases in which only negative test choices were available.