The purpose of this study is to construct interpretative arguments of the CSAT Writing Assessment based on the argument-based approach to validation and to suggest alternative approaches with validity. The adoption of the argument-based approach to validation has several positive effects, such as focusing attention on a broad array of issues inherent in the interpretations and uses of test scores, emphasizing the role of supporting assumptions and evidence, and allowing for the possibility of alternatives. This study constructed interpretative arguments in the category of “scoring, generalization, extrapolation, decision” and suggested ⒜ revising biases of measuring functions, ⒝ modifying artificial segments of writing processes, ⒞ reconstruction centered on writing-to-learn contexts, and ⒟ measuring of transferable capabilities based on those inferences.