Item Analysis  Updated on Dec 23, 2009  Item analysis is a
general term that refers to the specific methods used in
education to evaluate test items, typically for the purpose of
test construction and revision. Regarded as one of the most
important aspects of test construction and increasingly
receiving attention, it is an approach incorporated into item
response theory (IRT), which serves as an alternative to
classical measurement theory (CMT) or classical test theory
(CTT). Classical measurement theory considers a score to be the
direct result of a person's true score plus error. It is this
error that is of interest as previous measurement theories have
been unable to specify its source. However, item response theory
uses item analysis to differentiate between types of error in
order to gain a clearer understanding of any existing
deficiencies. Particular attention is given to individual test
items, item characteristics, probability of answering items
correctly, overall ability of the test taker, and degree