What I've tried to encourage people to do is to ignore what they think people expect of them, or what behaviors they might have to display at work, and focus on what comes naturally to them when they're on vacation or over the weekend. Theoretically that should help them get test results that are a little closer to their natural personality type rather than the personality that's expected of them at work or in other settings and that they feel they need to live up to.
But Marcus Buckingham, a speaker that I heard just last week (more on that here), has given me a new way to encourage people to determine their own personality types (or as Buckingham describes it, their strengths and weaknesses). He says that after an activity (it doesn't matter if it was in a group or alone, planned or spontaneous) we should evaluate the activity (or even the various parts of the activity) by determining whether we loved it or loathed it. If we loved it, then there's very likely something about that activity that played to our strengths. If we loathed it, then we were probably called upon to perform in a way that draws from our weaknesses.
The example he gave is that he recently attended a party with a lot of very famous people in attendance. Theoretically it should have been a great event that he would have enjoyed. But he loathed it. So he took that piece of information and tried to dial down to what exactly he loathed about it and found that he loathes mingling with people. (The description that he gave of how he felt while mingling described an introvert quite well.) On the other hand, he recently had to interview a woman that was a housekeeper at a hotel. The interview lasted about 30-45 minutes and by the end he realized that he had loved the experience. So he examined that reaction and determined that he really enjoys getting to know people on a deeper level.
Buckingham pointed out that just because you're good at something doesn't mean it's one of your strengths. You can be very good at something and still feel utterly drained by it at the end. Your ability to do the task well is therefore probably more a function of training and experience than innate ability or desire. According to his definition of a strength, what is important is not what we're good at so much as what energizes us. He gave an acronym that described this: SIGN
Success: When we're done, do we feel successful?
Instinct: What are we instinctively drawn to?
Growth: How do you feel when you're doing it? Is there a flow? Do you feel that you've grown?
Need: Does it feel like you've filled a need?
Obviously, what you're weak in will most likely leave you feeling unsuccessful, or you may not feel drawn to it at all - even if you have to do the job for some reason, or you'll feel stilted, or like the entire thing could have proceeded just fine without your input or help.
Buckingham also made a great suggestion for how to make the best of a situation that you usually find draining. He explained that though he hates mingling, he loves interviewing people. So instead of going to a party and mingling with 10 or 20 people, he'll find a person, interview them for awhile, find another person, interview them, find a third person and interview them. At that point he's had enough of talking with people and he heads for home. So when you're caught in a situation that plays to your weaknesses, find a way to insert your strengths into the picture.