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

• Measurement Scales in Social Science Research--Explanation of nominal and ordinal scales as well as measurement issues in general. From the Department of Psychology, Douglas College, British Columbia, Canada.
• Using Arrow Diagrams to Understand Claims--M. J. Peterson, University of Massachusetts, provides a comprehensive overview of arrow diagrams and how they are used.
• Variable Types--An overview of the different types of variables from the State University of New York.