120 likes | 288 Views
Political Science 30 Political Inquiry. 1. Homework #1 due today, start of lecture. 2. Sections meet in Solis 105 this week. Measurement I. Knowing a Good Measure When You See It. Conceptual and operational definitions of a variable Examples: Support for democracy Voter turnout in the U.S.
E N D
Political Science 30Political Inquiry 1. Homework #1 due today, start of lecture. 2. Sections meet in Solis 105 this week.
Measurement I. Knowing a Good Measure When You See It. • Conceptual and operational definitions of a variable • Examples: • Support for democracy • Voter turnout in the U.S. • Measurement error and validity
Conceptual Definitions • A conceptual definition of a variable states precisely what you mean when you use a particular term. • A society that “supports democracy” is one that emphasizes tolerance, trust, political activism, and Post-Materialist values, not just one that pays lip service to the ideals of democracy. -- Ronald Inglehart
Conceptual Definitions • A good conceptual definition: • Looks at how other scholars have defined a term, and goes with the consensus unless there is a good reason to deviate. • Allows you to test the theory that you want to test. • Is not circular (for example, does not say that support for democracy is when the public voices support for democratic values)
Operational Definitions • An operational definition of a variable is a complete recipe for going out into the world and measuring a variable. • It helps us make the leap from our subjective impressions to an objective measure. • Like a recipe in any good cook book, a good operational definition can be followed by any other chef.
Operational Definitions • To measure “support for democracy,” Inglehart uses the World Values/ European Values Survey from 1995-97 and 1999-2001 and looks at average levels of agreement with nine statements such as: • “Is it good to have a strong leader who does not have to bother with parliament and elections?”
Voter Turnout in the U.S.:The Traditional Measure • Conceptual: “Turnout” is the percentage of those who can vote who actually do. • The traditional operational definition is: Where Voting Age Population (VAP) includes noncitizens and convicted felons, but not citizens living overseas.
Voter Turnout in the U.S.:The McDonald & Popkin Measure • Conceptual: “Turnout” is the percentage of those who can vote who actually do. Where Voting Eligible Population is purged of noncitizens and convicted felons but includes citizens living overseas.
Measurement Validity • Measurement Validity gauges the strength of your empirical measures. It is highest when the gap between your conceptual definition and your operational definition is smallest.
Measurement Error Measured Value = True Value + Bias + Random Error Sources of Measurement Bias: • Faulty instruments: scale is always off, question wording always bad. • “Hawthorne Effect:” Humans behave differently when they are being tested