Operationalizing Concepts

Issues in operationally defining your concepts, validity,

reliability and scales

Review What is conceptualization? What is operationalization? Null Hypothesis construction: Ho (p. 605)

Logical, Value-neutral Asserts no difference between dependent and

independent variables Alternative Hypothesis: Ha (p. 145) Hypotheses and research questions

Operationalization Can anything be operationalized? “Those who get to ask the questions get to

determine the context of answers.” Operationalization and social justice Avoiding bias (p. 152)

Simple and complex operationalizations “covering the construct”

Operationalization in Action Try to operationalize these variables:

Teen mother Elderly Male homosexual Person with dementia Drug-abusing adolescent Criminal

Operationalization in Action, cont. Try to operationalize these variables

Love Peace Anxiety Insomnia Attachment Cognitive-behavioral therapy

Levels of Measurement (p. 172) Nominal Ordinal Interval Ratio

Measurement Error Random Error Systematic Error

How We Collect Data Direct self-report Indirect self-report Observation Archival records

Two Principles in Reducing Measurement Error Reliability

Definition: gives the same answer over time and among different populations and circumstances

Types of reliability Interrater reliability Test-retest reliability Internal consistency reliability

Inter-item correlations (p. 187)

Two Principles in Reducing Measurement Error Validity (p. 194)

Definition: Measures what it means to measure Face validity Content validity Criterion-related validity

Concurrent validity Predictive validity

Construct validity

Validity and Reliability, final words P. 198, for permutations Valid, but not reliable Reliable, but not valid Valid and Reliable

Constructing Measurement Instruments Why construct measurement instruments?

“Covering the construct” Complex constructs, subtle constructs Convergent and discriminant validity

No-nos when constructing measurement instruments (pp. 208 – 212)

Tools: Likert scaling Semantic differential scaling (p. 226)

Single-Systems Design Experiment Consider a behavior you want to

extinguish or increase Consider a reward and/or punishment