Research instruments are the tools and approaches used to collect data to answer the research question / hypothesis. More than one technique can be employed, the commonest are questionnaires and interviews. Research instruments or measures are the source of the actual data. These can be surveys, interviews, observation and measurement of demographic characteristics (gender, age, height, weight etc.) of the participants. Describing the measure is important because measures are the source of your data. All the results rest on whether or not the measures are adequate, whether measures help the reader judge the validity of the results or not.