How to Support Prescriptive Statements by Empirical Research: Some Missing Parts

摘要

This paper continues a discussion started in a special issue about the acceptability of prescriptive statements in educational research articles. In light of some ambiguities concerning what counts as a prescriptive statement, and the special issue's focus on causal relations as a requirement for the justification of prescriptive statements, a more detailed characterization of prescriptive statements and the structure of a complete argumentation for them is offered. This reveals two major obstacles to valid justifications of prescriptive statements that have received little attention before: the problem of normativity and the problem of generality. The proposed solution to the problem of normativity-that is, the impossibility to support prescriptive statements by empirical research alone-is to take into account that arguments for prescriptive statements target an audience that may agree on the values of many educational goals. The proposed solution to the problem of generality-that is, the necessity of well-established general causal regularities for the justification of prescriptive statements-requires appropriate designs for testing the generality of claims. Methodological suggestions include nested designs with quasi-representative samples of treatments as well as standard procedures for determining the cost and side effects on an agreed-upon set of relevant outcome dimensions for both current practice and any new intervention. If such steps are undertaken, prescriptive statements are no less justified in discussion sections than general descriptive claims as long as the final decision about them is suspended if the available normative and empirical arguments are not yet conclusive.