In this paper we have applied the data mining technique for knowledge discoveries on IGNOU science graduates by analyzing the relevant records with a view to facilitate science educators to apply the findings to support pedagogy in laboratory courses. A model construct "cuboid deep drilling", has been done to discover the most popular lab course combination. The paper also brings out the selectivity applied by students in opting lab courses, their preference towards different science disciplines, and their performance in practical examinations. In particular, about 37% students are active and only one-fourth of them attempt lab courses. Chemistry is the most popular and highest scoring subject among all disciplines offered by IGNOU.