Validation is one of the key aspects in data mining and even more so in educational data mining (EDM) owing to the nature of the data. In this chapter, a brief overview of validation in the context of EDM is given and a case study is presented. The field of the case study is related to motivational issues, in general, and disengagement detection, in particular. There are several approaches to eliciting motivational knowledge from a learner’s activity trace; in this chapter the validation of such an approach is presented and discussed
