Item Analysis in NCSSNCSS includes Item Analysis and Item Response Analysis tools. Use the links below to jump to the item analysis topic you would like to examine. To see how these tools can benefit you, we recommend you download and install the free trial of NCSS. Jump to: [Documentation PDF]
Item analysis studies the internal reliability of a particular instrument (test, survey, questionnaire, etc.). This instrument usually consists of several questions (items) which are answered by a group of respondents. Issues that arise include whether the instrument measures what was intended (e.g. Does a particular IQ test reliably measure an individual’s intelligence?), whether it produces the same results when it is administered repeatedly, whether it contains cultural biases, and so on.
Sample Output[Documentation PDF]
Item response analysis is concerned with the analysis of questions on a test which can be scored as either right or wrong. The goal of item response analysis is to determine how well questions on a test discriminate between individuals of varying ability.