Rediff.com has an article on the online CAT examination. This is a neat attempt at answering some of the typical FAQs aspirants of CAT have on the online format.
How will the computer-based CAT work?
CAT 2009 is likely to be based on one of two patterns used commonly for computerised tests:
Non-Adaptive Tests: These are similar to paper-pencil tests. You are tested on a "typical" test paper. Answers will be marked on a computer instead of an OMR sheet. Here you can skip, return to, or change your responses to a question at any point in time during the exam. You may or may not be allowed to see all the questions at the same time. Your answers are evaluated only at the end of the exam.
Adaptive Tests: GMAT and GRE are adaptive tests. You can see only one question at a time in an adaptive test, and you cannot skip it. You are not allowed to return to change your responses to previous questions. The questions in adaptive tests are decided while you are attempting the test. If you are not performing well, you are given easier questions, which are worth fewer marks; if you are doing well, you are given increasingly difficult questions, which are worth more marks.
Here is the link for the article to get answers on some more FAQs
