Quiz 2

Question 1

didn’t study, anxious, late to test

Answer 1

trait error

Question 2

error that resides in testing situation (noisy, hot, etc.)

Answer 2

Method errors

Question 3

what is the formula for test score theory

Answer 3

X (observed score) = t (true score) + E (error)

Question 4

What is the formula for gregory’s intelligence scale?

Answer 4

(Lf + Ll)x100 divided by

10

Question 5

___are used to estimate reliability.

Answer 5

Correlation coefficients

Question 6

ranges from -1.0 to +1.0

Answer 6

Correlation coefficients

Question 7

is expressed from 0.0 (no reliability) to +1.0 (perfect reliability)

Answer 7

reliability coefficient

Question 8

indicates the proportion of variance in a group of obtained scores that is attributable to true individual differences.

Answer 8

A reliability coefficient

Question 9

A reliability coefficient is directly interpretable. A test with a reliability of .90 has a ______ error.

Answer 9

.10

Question 10

What are the 4 types of reliability

Answer 10

test-retest
parallel form
internal consistency
interrater reliability

Question 11

-Stability of test scores over time
-It requires two administrations of the same test with the same group of individuals
-Correlate scores from one test taken at two different times.
Describes what type of reliability?

Answer 11

test-retest reliabiltity

Question 12

-Used when there is more than one form of a test
EX – SAT, Act, GRE, MCAT, Make-up Exams
-Reduces the possibility of coaching or cheating and memory or practice effects (minimizes but does not eliminate)
-measures degree that two forms of a test are measuring the same thing.
Describes what type of reliability

Answer 12

Parallel Form Reliability

Question 13

When you want to know if the items on a test assess one, and only one, dimension. The majority of psychological tests have only one form.
-correlate each individual item with the total score
Describes what type of reliability?

Answer 13

internal consistency reliability

Question 14

A single test is administered to a group of people
Items are divided into equal halves, typically odd-even (good especially b/c many tests get harder as test progresses)
Correlation between items is the split-half reliability
Have to be careful with speed tests, especially if first items are easier

Answer 14

Split-half reliability

Question 15

When you want to know whether there is consistency in the rating of some outcome. describes what type of reliability?
examine agreement between raters

Answer 15

interrater reliability

Question 16

How do we increase reliability

Answer 16

One way is to increase the number of items (typically works), will increase the range of test scores
EX – think of luck involved on a 5 item test vs. 100 item test.

Question 17

The average amount of variability in a set of scores (average distance from the mean) is called

Answer 17

standard deviation (s or sd)

Question 18

If s=____, there is no variability, numbers are identical in nature

Answer 18

0

Question 19

_____is sensitive to extreme scores, just like the Mean.

Answer 19

Standard deviation

Question 20

The Standard Deviation squared (or don’t compute last step of SD) is the ____

Answer 20

variance

Question 21

Second measure of internal consistency takes it a step further than split-half
Split-half has been criticized for lack of precision – reliability changes based on how items are split
Why not take a more typical value such as the mean of the split-half coefficients for all possible splitting of a test?
Used with dichotomous data- items scored as right or wrong dichotomous (0 or 1)

Answer 21

Kuder-Richardson Reliability

Question 22

mean of all possible split half coefficients, corrected by the Spearman-Brown formula.
Used for tests with continuum such as LIKERT
Must have high reliability coefficient (items must be homogenous – measure the same trait)

Answer 22

cronbach’s alpha (coefficient alpha)

Question 23

An advantage of the median over the mean is:
A) it is sensitive to extreme scores
B) it is less influenced by extreme scores
C) it is more accurately reflects the central tendency

Answer 23

B) it is less influenced by extreme scores

Question 24

The mean is:
A) the most frequently occurring score
B) the midpoint of a distribution of scores
C) least affected by extreme scores
D) the arithmetic average

Answer 24

D) the arithmetic average

Question 25

What is the mode of the following set of values?

13, 5, 17, 18, 5, 9, 9, 13, 5, 17, 5, 16

Answer 25

5

Question 26

In “descriptive statistics” you reduce the mass of the data, whereas with inferential statistics you:
A) measure a single characteristic
B) estimate a population’s characteristics
C) generalize information about a single person

Answer 26

B) estimate a population’s characteristics

Question 27

Reliability within a set of observations measuring homogenous traits of a construct (e.g., personality) is referred to as:
A) parallel forms reliability
B) unified reliability
C) internal consistency
D) all of the above

Answer 27

C) internal consistency

Question 28

A test has a reliability coefficient of .77. This coefficient means that:
A) 77% of the variance in test scores is true score variance, and 23% is error variance.
B) 77% of items on this test are reliable and 23% of the items are unreliable.
C) 23% of the variance in test scores is true score variance, and 77% is variance.

Answer 28

A) 77% of the variance in test scores is true score variance, and 23% is error variance.

Question 29

Test constructors can improve reliability by:
A) decreasing the number of items on a test
B) increasing the number of items on a test
C) retaining items that measure sources of error variation

Answer 29

B) increasing the number of items on a test

Question 30

The Spearman-Brown formula corrects for deflated reliability due to:
A) errors in validity
B) small sample size
C) systematic error
D) half-length tests

Answer 30

D) half-length tests

Question 31

Administering two supposedly equivalent forms of test (e.g. form A and form B) to the same group of individuals yields a correlation coefficient indicating:
A) test-retest reliability
B) split-half reliability
C) parallel forms reliability

Answer 31

A) test-retest reliability

Question 32

Approximately what value must a reliability coefficient have if a test is being used to make decisions about an individual’s life?
A) .90
B) .70
C) .50

Answer 32

A) .90

Question 33

A reliability coefficient can range from:
A) 0 to 1.00
B) 0 to 100
C) -1.0 to 1.00

Answer 33

A) 0 to 1.00

Question 34

The measure of how spread out numbers are in a group of numbers is the:
A) rooted variance
B) mean
C) internal consistency
D) standard deviation

Answer 34

D) standard deviation

Question 35

Explain the difference between reliability and validity.

Answer 35

Reliability is the ability of a test to be repeated with similar results and validity is the extent to which the test measures what it claims to measure.