Chapter 3 Flashcards
Defining and Measuring Variables
(Hypothetical) constructs
Hypothetical attributes or mechanisms that help explain and predict behavior in a theory.
Theory
A set of statements about the mechanisms underlying a particular behavior. Theories help organize and unify different observations of the behavior and its relationship with other variables. A good theory generates predictions about the behavior.
Operational definition
A procedure for indirectly measuring and defining a variable that cannot be observed or measured directly. An OD specifies a measurement procedure (a set of operations) for measuring an external, observable behavior and uses the resulting measurements as a definition and a measurment of the hypothetical construct.
Validity
The degree to which the measurement process measures the variable it claims to measure.
Face validity
Does the measurement technique look like it measures the variable that it claims to measure? Face validity is based on subjective judgment.
Concurrent validity
When scores obtained from a new measurement technique are directly related to the scores obtained from another, better-established procedure for measuring the same variable.
Predictive validity
When the measurements of a construct accurately predict behavior (according to the theory).
Construct validity
The scores obtained from a measurement procedure behave exactly the same as the variable itself. It is based on many research studies that use the same measurement procedure.
Convergent validity
A strong relationship between scores is obtained by two (or more) different methods of measuring the same constuct.
Divergent validity
Demonstrated by showing little or no relationship between the measurements of two different constructs.
Reliabilty
The stability or consistency of a measurement. If the same individuals are measured under the same conditions, it should produce (nearly) identical results.
Successive measurements: Test-retest reliability
Established by comparing the scores obtained from two successive measurements of the same individuals and calculating a correlation between the two sets of scores.
If alternate forms of the measuring instrument are used for two measurements, it is called parallel-forms reliability.
Simultaneous measurements: Inter-rater reliability
The degree of agreement between two observers who simultaneously record measurements of the behaviors.
Internal consistency: Split-half reliability
Obtained by splitting the items on a questionnaire or test in half, computing a seperate score for each half, and then calculating the degree of consistency between the two scores for a group of participants.
Scale of measurement (definition)
In general terms, measurement is a procedure for classifying individuals into categories. These categories are called SoM.