With the increasing adoption of interactive systems in healthcare, there is a need to ensure that the benefits of such systems are formally evaluated. Traditionally quantitative research approaches have been used to gather evidence on measurable outcomes of health technology. Qualitative approaches have also been used to analyze how or why particular interventions did or did not work in specific healthcare contexts. Mixed methods research provides a framework for carrying out both quantitative and qualitative approaches within a single research study. In this paper an international group of four informatics scholars illustrate some of the benefits and challenges of using mixed methods in evaluation. The diversity of the research experience provides a broad overview of approaches in combining robust analysis of outcome data with qualitative methods that provide an understanding of the processes through which, and the contexts in which, those outcomes are achieved. This paper discussed the benefits that mixed methods brought to each study.