Measurement Conceptualization Operationalization Level of Measurement Validity and

Measurement Conceptualization Operationalization Level of Measurement Validity and Reliability

Scientists can measure any thing that is “real, ” and most things that are not real. n n Much of what we study is made up Therefore, how can we measure something that is not “real” n Shared understanding of what a concept means

Conceptualization n An agreement about some observed social pattern n Produces concepts n n Terms that represent the shared agreement DANGER = Reification

Indicators n Some sign of presence or absence of a concept n Different indicators of the same concept “Behave the same way” = same dimension n Behave differently = possible that they tap different dimensions of the same concept n

Definitions of Concepts n n Real, Nominal, and Operational Definitions Clarification, expansion, and change in concepts n ANOMIE Overt time, consensus and clarity can emerge n Sometimes, concepts change over time, and things become less clear, or more complex n

Differences in operational definitions (or “indicators”) are more crucial for descriptive than for explanatory research WHY?

Operationalization: Decision Making n n Range of Variation Defining Variables and Attributes n Levels of measurement Nominal n Ordinal n Interval n Ratio n n Single versus Multiple Indicators

Measurement Quality n Precision and Accuracy n Reliability and Validity

How to Check/Demonstrate… n Reliability Test-retest n Split-half method n Inter-rater reliability n n Validity Face validity n Criterion & Construct validity n

Tension among reliability and validity n Reliability often comes by sacrificing some validity n n Fit with quantitative, structured, nomothetic methods More valid measures are often less reliable n Fit with qualitative, idiographic methods