In this article, we highlight the need for a precisely defined construct in score-based validation and discuss the contribution of cognitive theories to accurately and comprehensively defining the construct. We propose a framework for integrating cognitively based theoretical and empirical evidence to specify and evaluate the construct. We apply this framework to an example case for division of fractions. Methods used to evaluate the example case included task analysis of the mathematical proof for the invert and multiply algorithm, interviews with content and pedagogical experts, verbal protocols, and item analyses based on pilot test data. The proposed framework, however, is intended to be generalized to other constructs. (Contains 7 figures.)