1-11 Flashcards
quantitative item analysis
statistical analyses of the responses test takers gave to individual items
statistical analyses of the responses test takers gave to individual items
quantitative item analysis
item difficulty
the percentage of test takers who respond correctly
the percentage of test takers who respond correctly
item difficulty
how do we calculate item difficulty?
number of persons who answered correctly divided by number of persons who responded to the question
What do we do when items have a very low or high p value?
get rid of the item
low = 0 to .2 high = .9 to 1
When should an item be retained, with respect to its difficulty?
p = .5
item discrimination
extent to which items differentiate high from low scorers
extent to which items differentiate high from low scorers
item discrimination
How do we calculate the item discrimination index?
D = U - L
When should we retain an item to increase internal consistency?
retain those items that strongly differentiate high-scoring individuals from lower scoring individuals
What is an item characteristic curve (ICC) and what does it tell us about test items?
the line that results when we graph the probability of answering an item correctly with the level of ability on the construct being measured
provides a picture of the item’s difficulty and how well it discriminates high performers from low performers.
What is item response theory (IRT) and why has it become more popular for item analysis?
provide estimates of the ability of test takers that is independent of the difficulty of the items presented as well as estimates of item difficulty and discrimination that are independent of the ability of the test takers
When would we say a test question demonstrates item bias?
when an item is easier for one group than for another
What are the methods used for qualitative item analysis?
questionnaires for test takers
expert panels
