Model Selection of Nested and Non-Nested Item Response Models Using Vuong Tests

Abstract

In this paper, we apply Vuong’s general approach of model selection to the comparison of nested and non-nested unidimensional and multidimensional item response theory (IRT) models. Vuong’s approach of model selection is useful because it allows for formal statistical tests of both nested and non-nested models. However, only the test of non-nested models has been applied in the context of IRT models to date. After summarizing the statistical theory underlying the tests, we investigate the performance of all three distinct Vuong tests in the context of IRT models using simulation studies and real data. In the non-nested case we observed that the tests can reliably distinguish between the graded response model and the generalized partial credit model. In the nested case, we observed that the tests typically perform as well as or sometimes better than the traditional likelihood ratio test. Based on these results, we argue that Vuong’s approach provides a useful set of tools for researchers and practitioners to effectively compare competing nested and non-nested IRT models.     

The development of creativity in Chilean kindergarten and school children / Desarrollo de la creatividad en párvulos y escolares chilenos

Abstract

The purpose of this study is to explore the development of creativity in Chilean kindergarten and school children. For this, we evaluated non-verbal divergent and convergent thinking skills in a sample of 320 Chilean kindergarten, second-, fourth- and sixth-grade school children. We found that kindergarten and second-grade children showed a lower performance in creative fluency and originality than fourth-grade and sixth-grade children. In addition, we found that kindergarten and second-grade children had a low performance in creative elaboration, which worsened in the fourth and sixth grades. We did not find differences between the different educational levels in convergent thinking skills. Our results contradict previous international studies that report a stable development of creativity throughout the first few years of schooling, with a transitory slump in the fourth or sixth grade, revealing an early slump of creative skills in Chilean children, which rebound after the fourth grade. We discuss the potential relationship between the academization and rigidization of Chilean early childhood education and the early slump in creativity.