First problem: The Myers-Briggs test might not be a good measure of introversion/extroversion.
Because of the trouble I had placing myself in the extroverted as a Myers-Briggs INTP, I became interested in the type of M-B test questions that put me into the introvert category.
This is what Gifts Differing, by Isabel Myers, page 7, has to say:
“The introvert’s main interests are in the inner world of concepts and ideas.”
“The extrovert is more involved with the outer world of people and things.”
I pulled out the Myers-Briggs Type Indicator, Form G Self-Scorable (Revised), given to me and my husband by our friend who did Myers-Briggs for a living and who scored it for us (she died before I became fascinated by personality typing so I can’t go to her with questions). I counted the number of questions that pertained to I/E and came up with 21. Out of the 21 questions, 17 exclusively concerned relationships with people, 1 had to do with fashion, 1 had to do with things, and 2 weren’t oriented in any particular direction. I’ve picked out some test questions, along with my issues.
1. “When you are with a group of people, would you usually rather a) join in the talk of the group, or b) talk with one person at a time?” I don’t see how this would guarantee introversion or extroversion. Talking with 1 person rather than 4 doesn’t prove more of an inward focus, or even prove a more in-depth conversation. The question “Would you rather go to a party or stay home and read” would have a more direct connection with E and I, where the question as it’s phrased is geared more to finding out someone’s style of relating to people. In the past, I would have slipped through the cracks on this one, preferring to work the room and flirt with one man at a time.

This question would likely have other extroverts slipping through the cracks.
2. “At parties, do you a) sometimes get bored, or b) always have fun?” This measures how much you enjoy talking to almost anyone, just as long as there’s talk involved. It implies extroversion but again doesn’t prove it. If someone is bored with a party environment and much prefers a night out dancing, for example, that person would be labeled an introvert per this question. Like the previous question, it isn’t definitive…it can just as easily be measuring what an extrovert likes to do for fun as whether someone is an I or E. Again, opportunity for an extrovert to slip through the cracks.
3. “Which word in each pair appeals to you more: a) lively, or b) calm.” When someone is lively, enough of their energy is being used outwardly that a good guess would be extroversion, but someone who prefers calm could potentially be an extrovert. This question strongly implies extroversion but is not definitive enough.
I found problems with many other questions, but you get the gist. Test questions such as these should be more bomb proof.
Another problem with the I/E portion of the test is that it’s weighted very strongly in the direction of ascertaining I/E toward people and doesn’t measure orientation toward things. Since orientation toward things/the physical environment is part of the definition, Myers-Briggs doesn’t truly measure I/E because people who extrovert strongly toward the environment would likely be considered introverts on the test. The I/E part of the test is actually measuring people’s relationship toward other people and not only that, it’s jumping to the conclusion that if people aren’t oriented toward larger groups, they are introverts.
Second problem: According to the definition of an extrovert, a person can be focused on the environment, and nothing was said about an upper percentage of environment vs. people orientation that would still keep the person in the extroverted category. What category would someone fall in if they were more quiet but still solved their lack of connection with being/essence by focusing outward on the environment, the same way other extraverts focus on people? The quiet person would be playing the same extravert game as talkative people but would likely be classified as an introvert, and there are schools of thought that say introverts can have extraverted tendencies, and those that say no.
A connected question… Can someone be talkative but an introvert because they think so much while talking and listening? Can someone be more quiet but an extrovert because they’re so focused outward? Does amount of talking correlate directly to E/I or is it just an indication, not proof?