Chapter 3: Defining and Measuring Variables

Question 1

Theory

Answer 1

In the behavioural sciences, statements about the mechanisms underlying a particular behaviour.

Question 2

Constructs (hypothetical constructs)

Answer 2

Hypothetical attributes or mechanisms in a theory that help the theory explain and predict behaviour. Also known as hypothetical constructs.

Question 3

Operational definition

Answer 3

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 a measurement of the hypothetical construct.

Question 4

Validity

Answer 4

The degree to which the measurement process measures the variable it claims to measure.

Question 5

Ace validity

Answer 5

An unscientific form of validity that concerns whether a measure superficially appears to measure what it claims to measure.

Question 6

Concurrent validity

Answer 6

The type of validity demonstrated when scores obtained from a new measure are directly related to scores obtained from a more established measure of the same variable.

Question 7

Predictive validity

Answer 7

The type of validity demonstrated when scores obtained from a measure accurately predict behavior according to a theory.

Question 8

Construct validity

Answer 8

The type of validity demonstrated when scores obtained from a measurement behave exactly the same as the variable itself. Construct validity is based on many research studies and grows gradually as each new study contributes more evidence.

Question 9

Convergent validity

Answer 9

The type of validity demonstrated by a strong relationship between the scores obtained from two different methods of measuring the same construct.

Question 10

Divergent validity

Answer 10

A type of validity demonstrated by using two different methods to measure two different constructs. Convergent validity then must be shown for each of the two constructs. Finally, there should be little or no relationship between the scores obtained for the two different constructs when they are measured by the same method.

Question 11

Reliability

Answer 11

The degree of stability or consistency of measurements. If the same individuals are measured under the same conditions, a reliable measurement procedure will produce identical or nearly identical measurements.

Question 12

Test-retest reliability

Answer 12

The type of reliability found by comparing the scores obtained from two sequential measurements of the same individuals and calculating a correlation between the two sets of scores.

Question 13

Parallel-forms reliability

Answer 13

The type of reliability established by comparing scores obtained by using two alternate versions of a measuring instrument to measure the same individuals and calculating a correlation between the two sets of scores.

Question 14

Inter-rater reliability

Answer 14

The degree of agreement between two observers who simultaneously record measurements of a behavior.

Question 15

Split-half reliability

Answer 15

A measure of reliability obtained by splitting the items on a questionnaire or test in half, computing a separate score for each half, and then measuring the degree of consistency between the two scores for a group of participants.

Question 16

Ceiling effect

Answer 16

The clustering of scores at the high end of a measurement scale, allowing little or no possibility of increases in value.

Question 17

Floor effect

Answer 17

The clustering of scores at the low end of a measurement scale, allowing little or no possibility of decreases in value; a type of range effect.

Question 18

Experimenter bias

Answer 18

The influence on the findings of a study from the experimenter’s expectations about the study. Experimenter bias is a type of artifact and threatens the validity of the measurement as well as both internal and external validity.

Question 19

Single-blind

Answer 19

A research study in which the researcher does not know the predicted outcome for any specific participant.

Question 20

Double-blind

Answer 20

A research study in which both the researcher and the participants are unaware of the predicted outcome for any specific participant.

Question 21

Demand characteristics

Answer 21

Any potential cues or features of a study that (1) suggest to the participants what the purpose and hypothesis are, and (2) influence the participants to respond or behave in a certain way. Demand characteristics are artifacts and can threaten the validity of the measurement, as well as both internal and external validity.

Question 22

Reactivity

Answer 22

Participants’ modification of their natural behavior in response to the fact that they are participating in a research study or the knowledge that they are being measured. Reactivity is an artifact and can threaten the validity of the measurement as well as both internal and external validity.

Question 23

Laboratory

Answer 23

A research setting that is obviously devoted to the discipline of science. It can be any room or space that the subject or participant perceives as artificial.

Question 24

Field

Answer 24

Any research setting that the participant or subject perceives as a natural environment.