Paper 2

Measurement of Variables

One of the important aspects of conducting quantitative research is deciding how you will measure your variables. If you are not clear about what a variable is (e.g., gender) as opposed to a value of a variable (e.g., female, male) or the difference between an operational definition of a variable (i.e., how you will measure and code a variable) and a conceptual definition of a variable (i.e., an explanation of the construct in plain English) please see chapters 5 and 6 in Babbie (2002). If you do not know the different types of measurement reliability (e.g., test-retest, internal consistency), measurement validity (e.g., predictive, construct), or levels of measurement (i.e., nominal, ,ordinal, interval, and ratio) please see chapters 1- 3 in Walsh and Betz (2001) or chapters 1-5 in Thorndike (2005).

The first three chapters in Walsh and Betz (2001) cover 144 pages and do a good job of covering the basics of measurement including levels of measurement (nominal, ordinal, interval, and ratio), reliability (e.g., test-retest, internal consistency), validity (e.g., predictive, concurrent), types of scores (e.g., standard scores, percentiles), norms, and cultural issues. Chapters 1 - 5 of Thorndike cover 217 pages and go into more detail than Walsh and Betz. In addition, it includes other chapters on measuring attitudes and using rating scales (Chapter 12) and instrument development (Chapter 15).

You do not have to become an expert on these topics for the assignments in this course; however, you will need to know the basics when you work on the assignments that involve quantitative research.

References

Babbie, E. (2002). The basics of social research (2nd ed.). Belmont, CA: Wadsworth.

Thorndike, R.M. (2005). Measurement and evaluation in psychology and education. Upper Saddle River, NJ: Pearson.

Walsh, W.B. & Betz, N.E. (2001). Tests and assessment (4th ed.). Upper Saddle River, NJ: Prentice-Hall.