a confounder is a variable whose presence affects the variables being studied so that the results do not reflect the actual relationship. there are various ways to exclude or control confounding variables including randomization, restriction and matching. but all these methods are applicable at the time of study design. when experimental designs are premature, impractical, or impossible, resear...

This three part series of articles provides a brief overview of relevant research designs in nursing. The first article in the series presents the most frequently used quantitative research designs. Strategies for non-experimental and experimental research designs used to generate and refine nursing knowledge are described. In addition, the importance of quantitative designs and the role they p...