When I was first tested (I think about five years ago) it showed I am an INTJ. I retested myself two-three years later and it again showed INTJ. I think it described me fairly accurately and I liked the idea of a "scientist." I retested myself again a couple of months ago and it showed I am an INFP. I was baffled to say the least, as I thought the pattern was stable over time.
Tests initially showed I was on the brink between J and P so I understand that. But I scored slightly to moderately higher in Thinking while the new test showed a very high score for Feeling. That is too drastic a change for me to fully believe although my work as a teacher since the time of the original testing has made me more understanding and accommodating to people's needs. I would also be tempted to attribute the change to a progressed Moon in Cancer forming a grand water trine with Jupiter in Pisces and Venus, Mercury and Pluto in Scorpio. I feel changes in the types are to be sought in the progressed chart.
Other than that, I am as strong in introversion (Scorpio as the dominant sign in my chart) and intuition (Mercury in Scorpio conjunct Pluto, Neptune conjunct MC, Neptune sextile Venus, Neptune sesquiduadrate Moon, as well as Sagittarius as the second dominant sign in my chart (intuition in the type indicator is also large scale thinking vs focus on detail (which would be more characteristic of Gemini and Virgo).
The Thinking part in my previous testing I would attribute to Saturn conjunct Sun (an effect which is wearing off with time), generally well-aspected Mercury (exact trine with Jupiter in Pisces and conjunct Pluto to give it depth) and a very badly aspected Moon in Leo (square Mercury and Pluto, trine Uranus, trine Saturn. I view the last two placements as not very positive in terms of expressing the Moon's emotional and nurturing side.)
Judging versus Perceiving is an interesting tie. I would attribute Perceiving to the trine between Jupiter and the Scorpio planets, also to having a relatively strong mutable influence in my chart as well as North Node conjunct Ascendant which is progressively travelling through my 12th house.
I hope this helps and good luck with your testing! I think paralles like this one are extremely useful and really take astrology and psychology to the next level and thus the understanding of human character!
Edit a year and a half later: I retested myself again and it showed INTJ. Maybe the INFP result was related to the circumstances I was under at that time.