What are Computer Adaptive Tests?
1 minute
Ben explains how computer adaptive tests work and why they're more accurate than fixed form tests.
With Computer Adaptive Testing (CAT), the difficulty adjusts in real time based on how you're doing, getting harder after a correct answer and easier after an incorrect one. Each question also carries a weighting that reflects its difficulty, so a correct answer on a harder question counts for more than a correct answer on an easier one. This is how the test builds up an accurate picture of where your ability actually sits, rather than just counting how many you got right.
This provides each candidate with a unique testing experience, designed to reach the maximum level of precision in the minimum amount of time. By adopting this approach, adaptive tests show a greater level of accuracy, become much harder to cheat on by sharing questions, and provide a better candidate experience.
Computer adaptive testing is widely regarded as best practice, thanks to its speed, accuracy, and candidate experience.
How adaptive tests compare to traditional fixed tests
A one-size-fits-all approach simply doesn't work with psychometrics. One way to think of it is like a game of 20 Questions where your goal is to find out what number the candidate is thinking of between 1 and 1,000.
With fixed testing, you're using the same set of questions for everyone. You ask, "Is it bigger than 500?" The person says "No," but your next fixed questions are, "Is it bigger than 750?" and "Is it bigger than 850?". You're wasting time on irrelevant questions and not reacting to the information gained from previous questions and answers. This would be a very long, frustrating way to play and you might end up not knowing the exact number.
Adaptive testing is the normal, sensible approach to playing 20 Questions. When they say "No" to larger than 500, your next question immediately pivots to "Is it bigger than 250?" Every single question extracts maximum value, allowing you to zero in on the exact target in far fewer turns.
In this example, imagine the number you're looking for is the candidate's ability score.
One of the major weaknesses of fixed form tests is test security. If every candidate sees the same questions, what happens if an unscrupulous candidate leaks those questions? The test is now ruined, as anyone can simply download the questions and figure out the answers. Adaptive tests draw from an item bank of hundreds of questions, and each question is chosen based on how the candidate is performing. There's no fixed set of 10-20 questions to leak.
Adaptive tests won't stop candidates using AI tools to answer questions, though. For that, you need AI-resistant assessments.
Advantages of adaptive testing
- Shorter tests. Adaptive tests provide a comparable level of accuracy in roughly half the number of questions compared to fixed form tests, which means candidates can finish in half the time without any loss of precision.
- Better candidate experience. Candidates only see questions suited to their ability level, so they're not put off by questions that are too hard or bored by ones that are too easy. The result is a much more comfortable and engaging experience.
- Increased test security. Question banks containing hundreds of unique items make it very unlikely that any two candidates will see the same questions, which makes it significantly harder for candidates to share answers and keeps results trustworthy.
- Easy to keep up to date. Because adaptive tests draw from question banks, new items can be added and old ones retired without affecting how the test performs.
- Better at separating top candidates. Fixed tests struggle at the extremes. If most of the questions are too easy for strong candidates, they all bunch together near the top. Adaptive tests keep stretching them with harder questions, so you can tell a good candidate from an exceptional one, which matters most in competitive and graduate hiring.
Conclusion and next steps
If you're still using fixed form tests, adaptive testing is a no-brainer. You get more accurate results in less time, candidates have a better experience, and you're not left worrying about whether your questions are circulating online somewhere.
At Test Partnership, all of our cognitive ability assessments are fully adaptive. If you'd like to see how they work in practice, or just want to talk through whether they'd be a good fit for your hiring process, get in touch with our team and we'll walk you through it.
Primary author
Joshua Hancock
Head of Digital Marketing at Test Partnership. Over seven years' experience as a writer, content strategist, SEO and digital marketer.
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