1 Announcement Movie topics up a couple of days –Discuss Chapter 4 on Feb. 4 th –[ch.3 is on central tendency: mean, median, mode]

2 Conceptualization Process of specifying what we mean when we use particular terms. Produces an agreed upon meaning for a concept for the purposes of research. Describes the indicators we'll use to measure the concept and the different aspects of the concept.

3 Developing Measures Real Definitions –The true essence - Not practical Nominal Definition –Using a convention or consensus Operational Definition –Specify precisely how a concept will be measured

4 Babbie’s Example Anomie What does this mean? Societal condition of normlessness; social instability How do we define this concept? Durkheim uses it to describe societies Others use it to describe individuals –Some experience anomie

5 Anomie How do we measure anomie? Ask respondents if they agree with a set of statements See page 142 (Chapter 5) in Babbie –The lot of the average man is getting worse –Not fair to bring children into world the way things look for the future –Don’t know who you can count on –Public officials not interested in problems of average man

6 Political Science Example Political Apathy What does this mean? How are we going to measure this concept

7 Concepts A concept may have multiple dimensions –Religiosity examples –A belief dimension –A ritual dimension –A knowledge dimension Indicators –How do we observe religiosity? –Attending religious services Complex concepts are likely to have multiple dimensions and require multiple indicators

8 Reliability GENERAL DEFINITION: - Accuracy or precision of a measuring instrument. - Consistency - Similar results: stability, dependability predictability

9 Tests for Checking Reliability Test-retest method - take the same measurement more than once. Equivalence: use "essentially the same" measurement items on the same instrument or on different instruments and compare the answers (same time period). Split-half, Random half, alternate forms. Use established measures.

10 Internal Validity DEFINITION: the ability of the measuring instrument to measure one's theoretical concepts. METHODS OF ASSESSING VALIDITY: CRITERIAL-RELATED VALIDITY (predictive): predict to an outside criterion and compare the outcome to the outside criterion a. Concurrent: comparison to an existing or current outside criterion b. Predictive: comparison to a future outside criterion

11 Validity (cont.) CONTENT VALIDITY: representativeness of what is being measured to the intended concepts. Does it cover the range of meanings. FACE VALIDITY: obvious and self-evident content CONSTRUCT VALIDITY: degree to which a measure is related to other variables as expected within a system of theoretical relationships. A measure of martial satisfaction should be associated with a measure of marital fidelity. SAT score with college success. EXTERNAL -- concerned with the generalizability of the test/method