Abstract
Analysis of the cognitive structure of scientific competence in PISA-2006 by means of the Least Squares Distance Method (LSDM): The Spanish case. The cognitive diagnosis approach links Psychometrics and Cognitive Psychology in order to obtain detailed measurements of the processes and cognitive attributes required to solve test items. In this context, the Least Squares Distance Method (LSDM) employs item parameters, calibrated with any Item Response Theory (IRT) model, to analyze the attributes and provide evidence about the validity of the cognitive structure. The Organization for Economic Cooperation and Development (OECD) determines three cognitive attributes underlying students' performance in the PISA-2006 science items: a) identifying scientific issues, b) explaining phenomena scientifically and c) using scientific evidence. The aim of the present work is to analyze these processes and collect evidence of the cognitive structure proposed by the OECD, using the LSDM. A second aim is to compare the probabilities of mastering the attributes of the Spanish Communities. The results show that the proposed structure is appropriate to explain students' proficiency in the science items, and also, significant differences between three Spanish Communities were found.
