Development of Scientific Reasoning in College Biology: Do Two Levels of General Hypothesis-Testing Skills Exist?

The primary purpose of the present study was to test the hypothesis that two general developmentally based levels of hypothesis-testing skills exist. The first hypothesized level presumably involves skills associated with testing hypotheses about observable causal agents; the second presumably involves skills associated with testing hypotheses involving unobservable entities. To test this hypothesis, a hypothesis-testing skills test was developed and administered to a large sample of college students both at the start and at the end of a biology course in which several hypotheses at each level were generated and tested. The predicted positive relationship between level of hypothesis-testing skill and performance on a transfer problem involving the test of a hypothesis involving unobservable entities was found. The predicted positive relationship between level of hypothesis-testing skill and course performance was also found. Both theoretical and practical implications of the findings are discussed.