You can access Item Analysis once students have taken the test. To do so, go to your Grade Center. At the top of the Grade Center column for the test, click the dropdown and choose Item Analysis.
You’ll be taken to a screen with a list of all of the item analyses that have been run. To run the analysis on the test that you’ve selected, click Run.
If your test has a lot of questions or a lot of responses, this may take some time. You’ll get an e-mail when it’s complete. When it is, you’ll be able to click the link under Available Analysis to access it.
You’ll then be brought to the Item Analysis screen.
Each question is listed on the bottom with a number of statistics. Two that are emphasized are Discrimination and Difficulty.
Discrimination is the correlation between getting the answer right and doing well on the test. It ranges from -1 (doing well on the question means doing extremely poorly on the test) to 1 (getting the answer right yields a 100% on the test). If all students got the question right or wrong, discrimination can’t be calculated. Blackboard classifies the questions on the test based on 3 levels of discrimination:
Good Questions: questions with discrimination levels above 0.3
Fair Questions: questions with discrimination levels between 0.1 and 0.3
Poor Questions: questions with discrimination levels under 0.1
Difficulty is simply the percentage of students who got the question right (this is kind of counter-intuitive as a higher difficulty percentage means an easier question). There are 3 levels of difficulty:
Easy Questions: difficulty greater than 80%
Medium Questions: difficulty between 30% and 80%
Hard Questions: difficulty less than 30%
You can also click on a question for detailed information about the question.
