The strengths and weaknesses of research designs involving quantitative measures

This paper presents a critical review of the strengths and weaknesses of research designs involving quantitative measures and, in particular, experimental research. The review evolved during the planning stage of a PhD project that sought to determine the effects of witnessed resuscitation on bereaved relatives. The discussion is therefore supported throughout by reference to bereavement research. Three levels of quantitative research are presented: descriptive, correlational and experimental. The findings suggest that experimental research is subject to a number of methodological limitations that may jeopardise internal and external validity of the research results and, consequently, limit their applicability for practice. Nurses are therefore encouraged to carefully consider the virtues of experimental designs, in their quest for evidence-based practice and in the planning of future research.