Adolescents' under-standing of observation, prediction, and hypothesis in everyday and educational contexts

Adolescents' (N = 688, ages 11-17 years) understanding of the science-relat ed categories of observation, prediction, and hypothesis was tested via the Test of Hypothetico-Deductive Reasoning (THDR), developed by the authors. The THDR required the students to classify statements from everyday and edu cational contexts according to those 3 categories. Results indicated that t he students performed increasingly better from Grade 6 to Grade 11 on both the everyday and the educational context items (significant increases with each grade level, p < .001). In general, the students had considerable diff iculty in classifying the statements. Even the 11th-grade students, who had the best performance, obtained a mean score of 47.6% on everyday items and a mean score of 37.3% on educational context items. The authors conclude, despite some recent contrasting findings, that school curricula should incl ude development of students' hypothetico-deductive reasoning abilities.