This article outlines an illuminative evaluation study of the work-based module in a vocational qualification in Animal Health offered for the paraveterinary industry by a distance education institution in South Africa. In illuminative evaluation, a programme is studied by qualitative methods to gain an in-depth understanding of its "instructional system", its intended teaching arrangements, as well as its "learning milieu", the actual sites of learning interaction. This results in a rich description of the programme that allows "matches" and "mismatches" between the instructional system and learning milieu to be uncovered. In this study, this approach provided useful information relevant to the quality assurance of the module, and also generated significant insights about the design and delivery of work-based learning in vocational qualifications in general. (Contains 1 note.)