Criterion Problems in Conservation Research Reconsidered from a Psychometric Point of View

Summary Three types of scoring criteria for conservation tasks were distinguished: the judgment-only criterion and the two judgment-plus-explanation criteria, respectively, the Goldschmid and Bentler criterion and the Piagetian criterion. Ss were 462 children from kindergarten and primary schools, 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 Bentler criterion (i.e., according to the former criterion more children may be considered conservers than with the use of the latter criterion), whereas the Goldschmid and Bentler criterion was less stringent than the Piagetian one. The Piagetian criterion did not show a clear-cut factor structure, as was expected from Piaget's theory. In contrast, both the judgment-only criterion and the Goldschmid and Bentler criterion produced a reliable test for conservation and clear-cut factor structures, which showed a high degree of similarity. Although these two criteria may be considered satisfactory from a psychometric point of view, we must be aware that the use of one of the criteria in conservation research must be based on a theoretical framework.