Mining is a term used to describe the act of looking for something. Educational Data Mining (EDM) is an emerging discipline in the field of education that is concerned with gathering data through a set of preprocessed or rehearsed algiorithm. This is a machine embedded technique that records and analyze the behavior of the learners that uses a certain app or software.

Educational Data Mining is machine-learning, statistics, Data Mining (DM), psycho-pedagogy, information retrieval, cognitive psychology, and recommender systems that is designed to solve or resolve educational issues A. Dutt, M. A. Ismail and T. Herawan (2017). 

In this case, the Educational Data mining can tell us the effectiveness of a test or an assessment depending upon the responses of behaviours recorded by the machine that analyzes these behaviours. However, these machine reponse analytics can still be false in terms of data because a behaviour or pattern of one's responses can vary depending on the many things or factors that might influence the behaviour of an indicidual.

Source:

A. Dutt, M. A. Ismail and T. Herawan, "A Systematic Review on Educational Data Mining," in IEEE Access, vol. 5, pp. 15991-16005, 2017, doi: 10.1109/ACCESS.2017.2654247.