Concepts, Operationalization, & Measurement

1. Concepts, Operationalization, & Measurement Dr. Guerette

2. Conceptions & Concepts • These are the abstract mental images (concepts) that will be turned into terms that can then be conceptualized specifically into what we mean when we use particular terms.

3. Conceptions & Concepts • Conceptualization • The process by which we specify precisely what we mean when we use particular terms. • Indicators and dimensions • These are the end product of the conceptualization process that provides us with measures of our concept.

4. Conceptions & Concepts • Creating conceptual order • This is the process that will lead to measurable definitions for study. The order realizes that progression of measurement from a vague sense of a term to a specific measurement

5. Conceptual Order Conceptualization Conceptual definition Operational definition

6. Operationalization • This brings us one step closer to measurement by developing operational definitions, which specify what operations should be performed to measure a concept. This includes: • Scoring • Exhaustive & Exclusive measurement • Levels of measurement

7. Operationalization • Scoring • This represents another way of thinking about measurement in that it involves actually making observations and assigning scores or values.

8. Measurement as Scoring

9. Operationalization • Exhaustive Measurement • Exhaustive qualities of the attributes of a variable allow us to classify every observation. • Mutually Exclusive Measurement • Mutually exclusive attributes help researchers classify every observation in terms of only one attribute.

10. Levels of Measurement • Nominal measures - Are variables whose attributes are exhaustive and mutually exclusive and offer names or labels for characteristics. • Ordinal measures - Are variables whose attributes are exhaustive and mutually exclusive and can be logically rank ordered from greater than to less than. • Interval measures - Are those that have the same characteristic as nominal and ordinal but the logical distance between attributes can be expressed in meaningful standard intervals with zero having no meaning. • Ratio measures – Have the same characteristics as those above except that zero has meaning.

11. In Class Exercise Levels of Measurement • Indicate the level of measurement – nominal, ordinal, interval, or ratio – that describes each of the following variables: • Length of prison sentence (in months) • Attitudes toward the war in Iraq (strongly approve, approve, disapprove, strongly disapprove) • Sex of marine life handlers at Sea World • Type of childhood victimization (physical abuse, sexual abuse, neglect) • Height (in centimeters) • Score on a scholastic aptitude test • Place of birth • Number of years on a job (0-2 years, 3-9 years, 10 or more years) • Method of drug administration (snort, smoke, freebase, ingest, intravenous, inhalation, ingest) • Age at time of entering military service (under 18, over 18)

12. Two key standards for measurement quality Reliability - Refers to consistency. We look to be sure the measurement used will produce similar results over time. This can be achieved through the use of the Test-retest method, Inter-rater reliability, and The split-half method. Criteria for Measurement Quality

13. Validity - Simply put, means are you testing what you say you are testing? While more difficult to test for than reliability, ways of dealing with validity consist of Face validity – common agreement Content validity – adequate coverage of range of meanings Criterion-related validity – a comparison w/ an external measure Construct validity – based on logical relationships Multiple measures – comparison to alternative measures Criteria for Measurement Quality

14. Reliable but Not Valid

15. Valid but Not Reliable

16. Valid and Reliable

17. Composite Measures • Combine individual measures to produce more valid and reliable indicators. • Typologies – These are produced by the intersection of two or more variables to create a set of categories or types. • An index – Where there are two distinct conceptions that are combined in such a way to produce a measure that is more parsimonious than individual variables.