How to design an effective research study

The previous paper in this series (March 13) examined three methodological issues: sample selection, treatment and/or intervention and observation and measurement. Here, aspects of research design and procedures will be considered. Research design is important in helping to ensure that the results can be correctly interpreted and that observed changes can be attributed to the planned intervention rather than to other intervening factors. The description of the procedure explains how the selected methods were combined and describes the practical details of how the study was carried out.