Stats - Test Construction Flashcards
For a test to be good, what two things does it need?
Reliability and validity
Does validity or reliability involve consistency, repeatability and dependability in scores?
Reliability
What’s the formula of True Score Model or Classical Test Theory (i.e., total variability = ______ + _______)
total variability = true score variability + error variability (a combo of truth & error)
If true score variability is 80% then what percentage is error variability?
20%
total variability is always 100%
If true score variability is 80% then what is the reliability score?
0.80 (always expressed as a coefficient)
What’s the minimal acceptable reliability
0.80
What are 3 common sources of error in tests, and what are they?
- content sampling: items that do or don’t tap into a test-takers knowledge
- time sampling: scores are different at two points in time due to factors related to the passage of time
- test heterogeneity: when a test has heterogeneous items tapping more than one domain
How’s reliability increased in relation to number of items?
Reliability increases when the number of items increases
How’s reliability increased in relation to homogeneity of items?
the more homogeneous the items are, the greater the reliability
How’s reliability increased in relation to range of scores?
An unrestricted range of scores increases the reliability
Does the ability to guess increase or decrease reliability?
It decreases reliability
What is test-retest reliability?
When you administer the identical test to the same sample of people at two points in time
Coefficient of stability is another name for what?
Test-retest reliability
What’s parallel forms reliability?
It’s calculated by the scores obtained by the same groups of people on two roughly equivalent but not identical forms of the same test administered at two different points in time
Coefficient of equivalence is another name for what?
Parallel forms reliability
What type of reliability is when you look at the consistency of the scores within the test; therefore, the test is administered only once to one group of people
Internal consistency reliability
What are the two subtypes of internal consistency?
- Split-half reliability
- Kuder Richardson (KR-20/21) or Coefficient Alpha
What 1 of 4 reliability estimates is associated with the Spearman brown prophecy formula?
Internal consistency reliability in the subtype of split-half reliability
What is subtype called from internal consistency reliability where it finds the average of every possible way of splitting the test in half
Kuder Richardson or Coefficient Alpha
What reliability estimate looks at the degree of agreement between two or more scorers when a test is subjectively scored?
Interrater (interscorer) reliability
What reliability estimate connects to percent agreement, Pearson r, Kappa stats or Yule’s Y
Interrater reliability
If the test was perfectly reliable what would be the standard error of measurement score?
0.0