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Tuesday, December 13, 2011

What's the difference between the real MBTI® Assessment and a knock-off version?

Written by Catherine Rains

The main difference between the authentic MBTI® tool (published by CPP and no one else) and a knock-off version of the MBTI is the reliability and validity of each. The knock offs aren’t based on sound research, or usually any research at all, nor is the scoring method, so students will get inaccurate results much more often, up to 50% of the time. The reason some faculty and counselors love using the knock-offs, besides the fact they are usually cheaper, is that they think they are getting as accurate type with a knock off as with the real MBTI. Why do they think this? Simple – they take the knock off MBTI themselves to see if it comes up with their type, and lo and behold it does, 100% guaranteed! Problem with this validation method is that once you know your MBTI type, you can take the most invalid MBTI knock-off and still come up with your type. For instance, once you are clear that you have a preference for Extraversion, you will easily identify E/I questions, even poorly written ones, and you’ll almost always answer them in the E direction. Students who don’t know their type, on the other hand, will not have this level of self-knowledge, resulting in them being mistyped much more often and possibly making career decisions based on inaccurate information about their natural preferences.


  1. What great insight - I didn't think about the self-selection bias!