Have you got experience from different psychometric tests? Not all of those are available in the web, but some of them relate to MBTI and might give some clue about it.
I've done a short version of HBDI, Hermann Brain Dominance Instrument with both my own and my friends's answers of me. Here's some info on it ..
It measures brain dominance in four quadrants.
Upper right corner: holistic, intuitive, integrating, synthesizing.
lower right: interpersonal, feeling based, kinesthetic, emotional.
upper left: logical, analytical, fact based, quantitative
lower left: organized, sequential, planned, detailed.
I got highest in the upper right, closely followed by upper left, and slightly lower in lower right. A lot lower score in the lower left than in the others.
The theory suggests that people find it easier to have one half dominate (upper, lower, left or right), and hardest to have the opposite quadrants dominate. Haven't looked this up much tho, because I've found little info on the web.
Any differences or similarities with MBTI type theory, apart from that there are no type descriptions and two-valued divisions?