Runnign head: A DEVELOPMENTAL TEST FOR STAGE IDENTIFICATION 1 The Construction and Validation of a Developmental Test for Stage Identification: Two Exploratory Studies

The present work presents two exploratory studies about the construction and validation of the Inductive Reasoning Developmental Stage (IRDT), a forty-eight items test based on the Model of Hierarchical Complexity. The first version of the test was administered to a convenience sample composed by 167 Brazilian people (50.3% men) aged between 6 to 58 years (M = 18.90, SD = 9.70). The Rasch Model was applied, and the result shows reliability of .97 for the full scale. The Infit mean was .87 (SD = .28; Max = 1.69; Min = .39), and the person reliability was .95. One sample t-tests showed that the spacing of Rasch scores between items of adjacent orders of hierarchical complexity is significant, with large effect size. The second study was conducted in order to overcome some of the test’s limitations found in the first study. The revised IRDT were administered to a convenience sample composed of 188 Brazilian people (57.7% women) aged between 6 to 65 years (M = 21.45, SD = 14.31). The reliability for the full scale was .99, and its Infit mean was .94 (SD = .22; Max = 1.46; Min = .56). The person reliability was .95. One sample t-tests showed that the spacing of Rasch scores between items of adjacent orders of hierarchical complexity is significant, with large effect size. The paper finishes with a discussion about the necessity and importance to focus on the vertical complexity of the items in any test designed to identify developmental stages.