In the evaluation of drugs, the randomised double-blind placebo controlled trial is the ‘gold standard’. This method, based on a positivist paradigm, answers questions about efficacy and side-effects of treatments that are accepted as valid, reliable and generalisable, provided the study is well designed and properly conducted. In contrast, qualitative research methodologies, originating from the social sciences, embrace a variety of approaches, including phenomenological and other paradigms. Within clinical and health services research, qualitative approaches view the world more subjectively, acknowledging that the researcher is part of what is researched, focusing on meanings and understanding of experience, rather than on what can be reduced to quantitative measures. They can develop new ideas through induction from data, rather than confirming or refuting hypotheses. Qualitative methods have improved our understanding of the experiences of people with dementia and, if used alongside clinical trials, could be used to improve the relevance of outcomes to patients, compliance and user involvement. They could also possibly generate new measures of efficacy and effectiveness in severe dementia.