Lecture 3 - Reliability

Question 1

What is reliability?

Answer 1

Reliability is the proportion of obtained score variance explained by true score variance

Question 2

If rxx = .8 this means?

Answer 2

80% of variance in the obtained scores is due to true score variance and 20% is due to error score variance

Question 3

What formula will tell you the variance that is explained by error variance?

Answer 3

1-rxx

Question 4

Error variance in test-retest is due to what?

Answer 4

time sampling

Question 5

Error variance in alternate form (immediate) is due to what?

Answer 5

Content sampling

Question 6

Error variance in alternate form (delayed) is due to what?

Answer 6

time and content sampling

Question 7

Error variance in split-half is due to what?

Answer 7

content sampling

Question 8

What does the Spearman-Brown formula allow us to do?

Answer 8

Allows us to look at the effect on reliability of lengthening or shortening the test

Question 9

Do longer or shorter tests tend to be more reliable?

Answer 9

longer

Question 10

In split-half reliability, how long is the test?

Answer 10

half the length of the full test

Question 11

How can we use the Spearman-brown formula re split-half reliability?

Answer 11

to examine the effect on reliability of doubling the length of the test

Question 12

In an estimated true score, If the reliability of the score is perfect -(rxx=1) what does this mean?

Answer 12

their estimated true score is actually their obtained score

Question 13

In the standard error of measurement, if the reliability coefficient is perfect (rxx=1) what does this mean?

Answer 13

the standard error of measurement is 0

Question 14

In the standard error of measurement, if the reliability coefficient is equal to 0 what does this mean?

Answer 14

the standard error of measurement is equal to the standard deviation of the normative sample

Question 15

What is the standard error of difference?

Answer 15

the difference between test scores