Click on the following links. Please note these will open in a new window.

• The Zeepedia site has an extensive set of links to most research issues/tasks but this link focuses on theory, concepts and research and is followed on the same page by links to concepts, variables and hypotheses.
   
• This site contains a quite comprehensive but clear explanation of the main types of research variables and includes examples of these and how they relate to measurement scales.
   
• This site contains a good, clear exposition of variables, conceptual frameworks and hypotheses and how these are all linked together in the research process.
   
• Bangor University’s (UK) online research methods site has a good explanation of measurement, validity and reliability.