Abstract
[Reliability and Validity of Conservation Criteria]
Three types of scoring criteria for conservation tasks were distinguished: The judgment-only criterion and two judgment-plus-explanation criteria, respectively, the Goldschmid and Bentler criterion and the Piagetian criterion. Subjects were 462 children from kindergarten and primary school grades 1 to 6, who were given 13 conservation tasks. It was shown that the judgment-only criterion was less stringent than the Goldschmid and Bender criterion, whereas the Goldschmid and Bentler criterion was less stringent than the Piagetian one. The conservation tasks scored according the Piagetian criterion did not show a clearcut factor structure, as was expected from the theory. In contrast, both the judgment-only criterion and the Goldschmid and Bentler criterion showed to produce a reliable test for conservation and a clearcut factor structure. Furthermore these two factor-structures showed to have a high degree of similarity.