The motivation for this paper is the authors' recent work on several randomized control trials in which they found the primary result, which averaged across subgroups or sites, to be moderated by demographic or site characteristics. They are led to examine a distinction that the Institute of Education Sciences (IES) makes between "confirmatory"…

In this article, which is part of an ongoing research, a classification is proposed for ratio comparison problems, according to their context, their quantity type, and their numerical structure. Deriving from this classification, an interview protocol was designed, and guidelines for the interpretation of answers into strategies were decided. A…