Evidence-based practice (EBP) is a method of problem solving which involves identifying the clinical problem, searching the literature, evaluating the research evidence and deciding on the intervention. The best evidence is thought to be that obtained from controlled experimental work, and the least value is attached to the authority and clinical experience of the practitioner. While the term appears to have emerged largely from the McMaster University Medical School in Canada, it is increasingly linked with cost-effectiveness in today's NHS. There are a number of difficulties with the approach. Not all nursing problems are capable of being reduced to a clear issue that can be solved by scientific means and many require artistry to find a solution. There is a limited experimental research base from which to select interventions, and researchers applying for funding for non-experimental research may be disadvantaged. There may also be a temptation to use EBP to justify restricting the choice of interventions for both practitioner and patient.