This study provides empirical evidence for the Model of Hierarchical Complexity's ability to explain one major dimension of difficulty. That dimension is the hierarchical complexity of items in an instrument. The five instruments studied were: "Jesus' sayings", "Anti death penalty", "Helper-person problem", "To not report incest," and "To report incest." Each instrument consisted of five sets of items. Each item reflected one of five orders of hierarchical complexity, as had been done in previous work (Commons et al., 2006). Participants rated quality of the items on a 1 to 6 scale. In a factor analysis of all the tests together, most of the tests loaded highly on the first factor. This supports that stage of quite different tasks is a single factor. A Rasch analysis of performance of the 207 participants on each instrument was conducted. The relationship between hierarchical complexity of items and their Rasch scaled scores for each test was Jesus r3) = .828, Anti Death Penalty r(3) = .921, Helper-Person r(3) = . 990, Not to Report Incest r(3) = -.838, Pro Report r(3) = -.916. A Rasch analysis across all items for all instruments found that the items all fit on a single scale but sequentiality was not very good across domains. The factor analysis and regressions of Rasch stage scores on hierarchical complexity of items supported that test items were measuring stage thereby reflecting order of hierarchical complexity of task, providing support the Model of Hierarchical Complexity as one good predictor of task difficulty. |