Dr. Feldman’s paper constitutes a worthy continuation of the select pedigree of thorough neo-Piagetian theory constructions. It presents a general theory of stagewise cognitive development, in the spirit of Piaget’s naturalized epistemology. Theory construction at the general level at which Piaget operated has, for good reasons, an essential place in cognitive developmental psychology. In parti...

SUMMARY This report examines the meaning of validity and reliability and the role of psychometrics in plastic surgery. Study titles increasingly include the word "valid" to support the authors' claims. Studies by other investigators may be labeled "not validated." Validity simply refers to the ability of a device to measure what it intends to measure. Validity is not an intrinsic test property....