The Development and Validation of a Group Test of Logical Thinking

The paper describes the development of the Test of Logical Thinking (TOLT) to measure five modes of formal reasoning: controlling variables, proportional reasoning, combinatorial reasoning, probabilistic reasoning, and correlational reasoning. Each of the 10 items requires participants to select a correct response and justification from a number of alternatives. Analysis of data from 682 students from grades 6 through college indicated high test reliability (coefficient α = .85) and provided confirmation that the test measured one major underlying dimension termed formal thought. Evidence of criterion-related validity was obtained from a study in which 88 students from grades 10 through college were assessed on the TOLT and on five interview tasks. A correlation of .80 (p < .0001) suggested a strong relationship between the two measures of formal reasoning.