Chapter Summary

In answering political questions we need to be able to take our notions of key political concepts and measure them. The general process of measuring an attribute for the purpose of answering a question begins as you identify the cases you are studying. You will want to measure an attribute of those cases that varies. Define that attribute conceptually. Then define it operationally—how will you measure it? Next, evaluate the measure. How well does the measure line up with the concept? Is it valid? Is it reliable? Once you have decided how to measure your variable, you need to do so. Normally this means that you will set up a coding sheet for entering the data and fill it out. You then copy the data into a database, cleaning the data if necessary to make sure it is correct. At that point the variable is ready to be analyzed.

Learning Objectives

After reading this chapter, you should:

• Be able to identify the unit of analysis of a variable
• Know the difference between conceptual and operational definitions
• Know the levels of measurement
• Understand how to evaluate measurements according to their validity and reliability
• Know how to code a variable
• Be able to import an Excel file into SPSS
• Be able to produce a frequency table in SPSS
• Be able to create a professional looking frequency table in Word