This paper explores a trial of an educational intervention designed for people who have Type 2 diabetes. The aim of the trial was to understand how the intervention had influenced outcomes in the context of participants' everyday lives. A randomised-controlled wait-list trial design was used. The study was also informed by a qualitative approach which explored the meanings held by participants for informing their behaviours. Outcomes were measured using diabetes-specific questionnaires and clinical measures of blood glucose control, weight and drug treatment. Alongside these, focus group discussions were held to explore how outcome effects had transpired. Using these different methods resulted in two separate data sets which required diverse methods for analysis. This paper uses examples of compatibilities and contradictions between the data sets to look at how they were combined to produce valid results. Conclusions drawn showed that a combined methods approach was essential to expand the scope and improve the analytic power of trials of patient education. It produced illuminating results which provided guidelines for practice and suggested further areas for research.