Test Integrity

Test integrity is a percentage that refers to how much a test has changed since it was created. Because tests are made up of live lexical items, it's possible to change a test drastically simply by editing the items that are used within it. Now, if you usually enter in correct lexical item information the first time and don't change it (adding information is ok) then most all of your tests will continue to have 100% integrity. Additionally, it should be a rare event that you delete an item because of the possibility that some test still references it. However, doing so will not make the test unusable. It will only cause the test to have one less question.

The problem is that test statistics like the average score have less and less significance as the integrity decreases. This is because some past test scores that were used to calculate the average score apply to a different version of the test than the one that exists now. This is probably not a big deal in the case where an item's definition changed slightly or its lexical type had to be corrected. In these cases, new test scores are still comparable with older scores. It's only when many questions have changed or items have been deleted that a test's statistics lose significance. In these situations it might be a good idea to rebuild the test so that once again you can reliably track your progress.

Note that when questions are missing do to lexical items that have been deleted there will be 2 numbers showing in the Questions column of test dialog windows. The first number will be the number of valid questions still in the test. The second number will be the original number of questions that the test had when it was created. This number is enclosed by parentheses.