Occupational health nurses in clinical practice are in an excellent position to identify unanswered questions that affect the health and well being of employees. Once these questions have been asked, the occupational health nurses may proceed with structured research to find answers. The research begins with a thorough review of existing literature to learn the background of the issue and clearly define a research question. This question is then framed conceptually to guide the study. The theoretical framework may be supported or refuted by the research project. The study method is dictated by the research question and the theoretical framework. Two basic research methods are intervention and descriptive studies. Intervention studies, with treatment and control groups, attempt to show differences between groups when one receives a certain treatment and the other group does not. Descriptive studies generally survey attitudes or activities, then test for associations. Data analysis is determined by the type of study and type of data collected. Descriptive statistics generate frequencies and correlations; inferential statistics yield stronger information about associations of the variables. Interpretation of research findings must include consideration of threats to validity. Internal validity allows the investigator to state with confidence that the intervention was responsible for the difference between the groups. External validity allows for generalizability of the findings to other populations. The purpose of nursing research is to advance the discipline of nursing. Research refines nursing theories and guides practice. It is through research that occupational health nurses gain confidence to alter procedures and provide interventions that have been shown to be effective.