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Tuesday, March 28, 2006

Take the Cognitive Reflection Test!

Charlie is napping. For the second day in a row Charlie has insisted on wearing his superhero pajama bottoms over his pants. Quite a few people have noticed the new look. One guy at Starbucks commented that Charlie was starting a new trend, and that I should “trademark his look”. Another customer commented that the outfit was a clever solution to a problem she encountered while dressing her own sons. She’s right; it is a simple solution to a common problem.

As for me, I’ve been reading a lot about the brain, assessment, and video gaming lately and came across something called the Cognitive Reflection Test (CRT). According to its creator, Dr. Shane Frederick of MIT, the Cognitive Reflection Test is valuable “for researchers interested in separating people into cognitive groups, the CRT is an attractive test: it involves only three items and can be administered in a minute or two, yet its predictive validity equals or exceeds other cognitive tests that involve up to 215 items and take up to 31⁄2 hours to complete.”

In fact the CRT has a high correlation with the ACT and the SAT tests. So in honor of testing season why not give it a go? Did I mention that it is only 3 questions long?

Grab a pencil!

Answer the following questions:

(1) A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball.
How much does the ball cost? _____ cents

(2) If it takes 5 machines 5 minutes to make 5 widgets, how long would it take
100 machines to make 100 widgets? _____ minutes

(3) In a lake, there is a patch of lily pads. Every day, the patch doubles in size.
If it takes 48 days for the patch to cover the entire lake, how long would it
take for the patch to cover half of the lake? _____ days

All of the questions have intuitive “BLINK” answers. The thing is, those answers are wrong. For example, most folks “see” the answer to the first question right away. The ball costs 10 cents, right?

Wrong, the ball actually costs 5 cents. Set up and run the equation yourself. For the math challenged, check this out:


B=C + 100

The ball costs 5 cents.

Now, if you take the time to think through all the problems, and check your work, then you are more apt to get the correct answers. If I had students who were going to take the ACT or SAT, I’d give them this test to demonstrate the limits of intuition.

The answers are: 5 cents, 5 minutes, and 47 days.

Thanks to Eide Neurolearning Blog for getting me into CRT.

Comments on "Take the Cognitive Reflection Test!"


Blogger ccpo said ... (10:04 AM) : 

If I got 3 of 3, I assume I'm a fox, not a hedgehog, eh?


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