In this study, tools for understanding of `educational effectiveness` were used to grasp the conceptual structure of educational effectiveness, which is the objective of this study, and develop the concept. The typicality of educational effectiveness was observed by critically analyzing the concept, and the context of conceptual individuality for the concept was found by collecting and studying cases. First, the concept is specified based on measuring the aspect of changes in learners, and the factors that cause the changes. Second, the concept can be identified with the result of goal achievement when based on the changes. And, the third is means-ends approach. In addition, as a result of investigating existing cases on the concept of educational effectiveness, it has been concluded that the following common criticisms must be solved for the concept to be individualized. The criticisms include first, the behavior that specifies the concept as a measurable change; second, causal belief based on functional reduction; and third, the stance on considering all school activities as education.