Chapter 3: Constructs and Operational Definitions
Behaviour measure
a manner in which researchers can observe constructs in overt behaviours such as laughing, playing, eating, sleeping, arguing or speaking. Behavioural measures provide researchers with a vast number of options making it possible to select the behaviours that seems to be best for defining and measuring the construct.
Validity
a measurement procedure is the degree to which the measurement process measures the variable that it claims to measure.
Operational definition
a procedure for indirectly measuring and defining a variable that cannot be observed or measured directly. An operational definition specifies a measurement procedure (a set of operations) for measuring an external, observable behaviour , and uses the resulting measurements as a definition and measurement of the hypothetical construct.
Theory
a set of statements about the mechanisms underlying a particular behaviour. Theories help organize and unify different observations of the behaviour and its relationship with other variables. A good theory generates predictions about the behaviour.
Face validity
an unscientific form of validity demonstrated when a measurement procedures superficially appears to measure what it claims to measure
Demand characteristic
any of the potential cues or features of a study that (1) suggest to the participants what the purpose and hypothesis is, and (2) influence the participants to respond or behave in a certain way
Laboratory
any setting that is obviously devoted to the discipline of science; it can be any room or space that the subject/participant perceives as artificial
Double-blind
both the researcher and the participants are unaware of the predicted outcome
Convergent validity
demonstrated by a strong relationship b/w the scores obtained from two or more different methods of measuring the same construct
Divergent validity
demonstrated by showing little or no relationship b/w the measurements of two different constructs
Predictive validity
demonstrated when scores obtained from a measure accurately predict behaviour according to a theory
Concurrent validity
demonstrated when scores obtained from a new measure are directly related to scores obtained form an established measure of the same variable
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
Physiological measure
examine the physiological manifestations of the underlying construct; example: fear = increased heart rate
Constructs
hypothetical attributes or mechanisms that help explain and predict behaviour in a theory
Parallel-forms reliability
if alternative versions of the measuring instrument are used for the two measurements during test-retest reliability
Split-half reliability
obtained by splitting the items on a questionnaire or test in half, computing a separate score for each half, and then calculating the degree of consistency b/w the two scores for a group of participants
Reactivity
occurs when participants modify their natural behaviour in response to the fact that they are participating in a research study or the knowledge that they are being measured
Experiment bias
occurs when the measurements obtained in a study are influenced by the experimenter's expectations or personal beliefs regarding the outcome of the study
Field
place that the participant/subject perceives as a natural environment
Construct validity
requires that the scores obtained from a measurement procedure behave exactly the same as the variable itself. Construct validity is based on many research studies that use the same measurement procedure and grows gradually as each new study contributes more evidence.
Single-blind
researcher does not know the predicted outcome
Self report measure
self-reported; primary advantage is that the most direct way to assess a construct
Reliability
stability of consistency of the measurement; if the same individuals are measured under the same conditions' reliable measurement procedure produces identical (or nearly identical) measurements.
Ceiling effect
the clustering of scores at the high end of a measurement scale, allowing little or no possibility of increases in value
Floor effect
the clustering of scores at the low end of a measurement scale, allowing little or no possibility of decreases in value
Apprehensive subject role
the participants are overly concerned that their performance in the study will be used to evaluate their abilities or personal characteristics; they are trying to place themselves in a desirable lightly responding in a socially desirable fashion, instead of truthfully
Faithful subject role
these participants attempt to follow instructions to the letter and avoid acting on any suspicions that they have about the purpose of the study
Negativistic subject role
these participants have identified the hypothesis of the study and are trying to act contrary to the investigators hypothesis
Good-subject role
these participants have identified the hypothesis of they study and are trying to produce the responses that support the investigators hypothesis
Positive relationship
two measurements change together in the same direction
Negative relationship
two measures change in opposite directions so that people who score high on one measure tend to score low on the other.