Chapter 3: The Measurement of Behaviour

Question 1

Psychometrics

Answer 1

The study of psychological measurement.

Question 2

Converging Operations

Answer 2

Measuring a construct in several different ways (e.g. combining observational, physiological, and self-report measures).

Question 3

Nominal Scale

Answer 3

Numbers assigned are simply labels for characteristics or behaviour (e.g. Males = 1, Females = 2).

Question 4

Ordinal Scale

Answer 4

The rank ordering of people’s behaviours or characteristics (students’ ranking from lowest to highest in a class). An ordinal scale does not tell us the distance between participants on the variable being measured.

Question 5

Interval Scale

Answer 5

Equal differences between the numbers reflect equal differences between participants, but there is no true zero point (e.g. scores on an IQ test).

Question 6

Ratio Scale

Answer 6

Equal differences between the numbers reflect equal differences between participants, and there is a true zero point (e.g. weight).

Question 7

Observed Score

Answer 7

True Score + Measurement Error

Question 8

True Score

Answer 8

The score that a participant would have obtained if the measure were perfect and we were able to measure without error.

Question 9

Measurement Error

Answer 9

Variability in scores due to factors that distort the true score.

Question 10

Five Sources of Measurement Error

Answer 10

1. Transient States: A temporary, unstable state of the participant (e.g. mood).
2. Stable Attributes: Enduring traits of the participant (e.g. illiteracy).
3. Situational Factors (e.g. characteristics of the researcher or research setting).
4. Characteristics of Measure (e.g. ambiguous wording).
5. Mistakes in Recording a Participant’s Score

Question 11

Reliability

Answer 11

The consistency or dependability of a measuring technique. Usually expressed as a correlation coefficient.

Question 12

Correlation Coefficient

Answer 12

Expresses the strength of the relationship between two measures.

Question 13

Test-Retest Reliability

Answer 13

Consistency of participants’ responses on a measure over time.

Question 14

Interitem Reliability

Answer 14

Assesses the degree of consistency among the items on a scale. Tells us whether all of the items on a scale are measuring the same thing. If not, summing scores across the items creates measurement error and lowers reliability.

Question 15

Item-Total Correlation

Answer 15

The correlation between a particular item and the sum of all the other items on the scale (ideally > .30).

Question 16

Split-Half Reliability

Answer 16

Divide the items on a sccale into two sets and examine the correlation between the sets.

Question 17

Cronbach’s Alpha Coefficient

Answer 17

Equivalent to the average of all possible split-half reliabilities (adequate if > .70).

Question 18

Interrater Reliability

Answer 18

The consistency among two or more researchers who observe and record participants’ behaviour.

Question 19

How can we increase the reliability of measures?

Answer 19

1. Standardize administration of the measure.
2. Clarify instructions and questions.
3. Train observers.
4. Minimize error in coding data.

Question 20

Validity

Answer 20

The degree to which a measurement procedure actually measures what it is intended to measure rather than measuring something else (or nothing other than error).

Question 21

Face Validity

Answer 21

The extent to which a measure appears to measure what it’s supposed to measure.

Question 22

Construct Validity

Answer 22

The extent to which a measure of a hypothetical construct relates as it should to other measures.

Question 23

Convergent Validity

Answer 23

A type of construct validity that assesses the extent to which a measure correlates with other measures that it should correlate with (e.g. embarrassability should be positively associated with shyness but negatively correlated with self-confidence).

Question 24

Discriminant Validity

Answer 24

A type of construct validity that assesses whether a measure does not correlate with other measures that it should not correlate with (e.g. embarrassability should not correlate with IQ).

Question 25

Criterion-Related Validity

Answer 25

The extent to which a measure allows us to distinguish among participants on the basis of a particular behavioural criterion. Researchers examine whether behavioural outcomes are related to scores on the measure as expected.

Question 26

Concurrent Validity

Answer 26

A type of criterion-related validity that assesses the extent to which scores on a measure are related as expected to a criterion that is assessed at the time the measure is administered (e.g. an embarrassability scale administered today predicts blushing in the current situation).

Question 27

Predictive Validity

Answer 27

A type of criterion-related validity that assesses the extent to which scores on a measure are related as expected to a criterion that is assessed in the future (e.g. an embarrassability scale administered today predicts whether students sign-up for public speaking classes next semester).

Question 28

Test Bias

Answer 28

Occurs when a particular measure is not equally valid for everyone.