This paper presents a case study of a university’s discrete mathematics course with over 170 students who had access to an online learning environment (OLE) that included a variety of online tools, such as videos, self-tests, discussion boards, and lecture notes. The course is based on the ideas of the Personalised System of Instruction (PSI) modified to take advantage of an OLE. Students’ learning is initially examined over a period of 2 years, and compared with that in a more traditionally taught part of the course. To examine students’ behaviour, learning strategies, attitudes, and performance, both qualitative and quantitative techniques, were used as a mixed methodology approach, including in-depth interviews (N=9), controlled laboratory observations (N=8), surveys (N=243), diary studies (N=10), classroom observations, recording online usage behaviour, and learning assessments. In addition, students’ attitude and performance in 2 consecutive years where PSI was applied to the entire course provides further understanding that is again in favour of PSI in the context of OLE. This chapter aims to increase understanding of whether PSI, supported by an OLE, could enhance student appreciation and achievement as findings suggest.