I took the Birkman first look assessment today. It is part of the outplacement assistance provided by my former employer. It is an online survey in 3 parts. First 125 true false questions about what people in general are like. Next the same (I think) 125 questions with reference to yourself. And finally 48 questions in which you are given 4 job choices and you are asked for a first and second choice (assuming you are qualified and they pay equally).
I found the first part difficult as I often felt completely unsure about things like the average person's work habits or preferences. So I tended to go by my own example a lot which probably defeats the purpose a bit. The second part was straightforward enough although a few questions were poorly worded. I also had a bit of trouble with the third part as assuming I was qualified for jobs I am totally unsuited for was a bit of a stretch and also I don't really have a good idea about what you actually do in some of the jobs (like toolmaker or even clerk).
After completing the questions you receive a fancy color coded assessment. I find it hard to take the results too seriously, apart from a few obvious points (like I am not cut for a position in sales) it seemed too much like the horoscopes you see in newspapers. Although I suppose it does have some value in making you think about career alternatives.