Chapter 4 - Reliability

Question 2

Definition please:

What is Cronbach’s alpha?

Answer 2

A measure of internal consistency reliability in testing and assessment

Values close to 1 indicate high reliability.

Question 3

Definition please:

What does reliability in psychological testing refer to?

Answer 3

The consistency with which a test measures what it is intended to measure

It allows users to generalize conclusions from test scores.

Question 4

Definition please:

Define true scores in the context of psychological assessment.

Answer 4

Hypothetical scores obtained if a test were perfectly reliable and free from measurement error.

Question 5

Definition please:

What are estimated true scores?

Answer 5

Theoretical scores a test-taker would achieve without measurement errors influencing actual test results.

Question 6

Definition please:

What do confidence intervals for test scores represent?

Answer 6

The range of scores within which the true scores of individuals are likely to fall.

Question 7

Definition please:

What is the Standard error of measurement (SEM)?

Answer 7

An index of measurement error that indicates the precision or reliability of individual test scores.

Question 8

Definition please:

What does unsystematic error variance mean?

Answer 8

Unpredictable factors contributing to errors in test scores.

Question 9

Definition please:

Define systematic error variance (bias).

Answer 9

Predictable and consistent inaccuracies in measurement affecting test scores.

Question 10

Definition please:

What is true score variance?

Answer 10

The proportion of observed score variance attributable to actual differences in the construct being measured.

Question 11

Definition please:

What are observed scores?

Answer 11

The actual scores obtained by individuals on a test or assessment.

Question 12

Definition please:

What does test-retest reliability assess?

Answer 12

The consistency of test results over time by correlating scores from multiple testing occasions.

Question 13

Definition please:

What are parallel forms in psychological testing?

Answer 13

Multiple versions of a test that are equivalent in content and difficulty level.

Question 14

Definition please:

Define split-half reliability.

Answer 14

An estimate of reliability obtained by correlating scores on two halves of a test.

Question 15

Definition please:

What does internal consistency refer to?

Answer 15

The extent to which items in a test are interrelated and measure the same underlying construct.

Question 16

Definition please:

What is content sampling (domain sampling)?

Answer 16

How test scores reflect a broader range of potential items, introducing measurement error.

Question 17

Definition please:

What is time sampling in psychological tests?

Answer 17

Observing behavior during specific time intervals to assess consistency and variability in performance.

Question 18

Definition please:

What is the Kuder-Richardson coefficient?

Answer 18

A type of internal consistency reliability measure assessing item correlation within a test.

Question 19

Definition please:

Define the domain-sampling model.

Answer 19

A theoretical framework explaining how test scores are influenced by a range of potential items.

Question 20

Definition please:

What does equivalent forms reliability refer to?

Answer 20

The consistency of a test when two alternate forms are administered to the same group.

Question 21

Definition please:

What is** generalisability theory**?

Answer 21

A set of ideas and procedures emphasizing context in assessing the reliability of evaluations.

Question 22

Definition please:

What is inter-rater reliability?

Answer 22

The extent to which different raters agree in their assessments of the same sample.

Question 23

Definition please:

What is a reliability coefficient?

Answer 23

A measure used to assess the consistency and dependability of memory tests.

Question 24

Definition please:

What does test-retest reliability measure?

Answer 24

The consistency of test scores when the same test is administered on different occasions.

Question 25

# *Definition please:* Define **Parallel forms reliability**.

Answer 25

The consistency of test scores obtained from different but equivalent forms of the same test.

Question 26

# *Definition please:* What is a **true score estimate**?

Answer 26

The confidence interval surrounding an individual's actual score on a psychological test.

Question 27

# *Definition please:* What does a **95% confidence interval** for test scores indicate?

Answer 27

A range of values within which the true test scores are estimated to lie with 95% certainty.

Question 28

# *Definition please:* What is the **Spearman-Brown formula** used for?

Answer 28

To estimate the reliability of a test when the test length is changed or extended.

Question 29

# *Equation time:* What is **Cronbach's alpha**equation?

Answer 29

α=(k÷[k−1])(1 −[Σσi^2÷σt^2 ]) ## Footnote * α= Cronbach’s alpha coefficient * k= number of items in the test * σ_i 2 = the sum of each test item’s variance * σ_t 2= the variance in total scores on the test

Question 30

# *Equation time:* What is **Standard error of Measurement** equation?

Answer 30

SEM=SD×√(1−r_XX) ## Footnote * SEM = standard error of measurement * SD = standard deviation of test * r_xx = reliability coefficient of test

Question 31

# *Equation time:* What is the **True Score Estimate** equation?

Answer 31

X_T= r_XX (X_0−X ̅ )+ X ̅ ## Footnote * X_T= individual’s estimated true score on measure * r_XX= reliability coefficient of measure * X_0= individual’s observed score on measure * X ̅= mean score on measure

Question 32

# *Equation time:* What is the equation for **95% confidence interval for test scores - upper limit**?

Answer 32

Upper limit= X_0+ Z_95 (SEM) ## Footnote * X_0= Individual’s observed test score (or estimated true score) * SEM= standard error of measurement * Z_95= Z value beyond which 2.5% of possible scores lie

Question 33

# *Equation time:* What is the equation for **95% confidence interval for test scores - lower limit**?

Answer 33

Lower limit= X_0+ Z_95 (SEM) ## Footnote * X_0= Individual’s observed test score (or estimated true score) * SEM= standard error of measurement * Z_95= Z value beyond which 2.5% of possible scores lie

Question 34

# *Equation time:* What is the **Spearman-Brown formula relating reliability to test length**?

Answer 34

k= (r_(yy ) (1 − r_xx))/(r_(xx ) (1 − r_yy)) ## Footnote * k= the factor (multiplier) by which test length is to change (e.g., if k=2, test length doubles; if k=0.5 test length halves) * r_xx= reliability of original test * r_yy = reliability of test after change to test length