Social work and welfare education plays an important role in preparing students for critical assessment of evidence and knowledge claims. Just as academics and practitioners develop preferences for particular theory and practice paradigms, they also have assess to differing research paradigms. Unfortunately, 'qualitative' and 'quantitative' are often used as shorthand for research paradigms. The YP4 Outcome Evaluation is an example of a randomised controlled trial that is being conducted within a critical rather than a positivist paradigm. I propose that an evidence-based practice model may be expanded and enriched to include research, reflection and theory as credible evidence for practice. We need this rich evidence for advocacy work to change social policy and bring better services to the people we serve.