The dominant function is different, Fi vs Ti, but the secondary "extroverted intuition" should lead the thinkers down similar paths or along similar patterns. There is a lot of typology information out there, and some of it is contradictory, but I did read somewhere that INFP's and INTP's are remarkably similar. I think it is in Kiersey's "Please Understand Me." In my personal experience, I have found them to be somewhat similar in that they spend a good deal of time in somewhat detached reverie, and because I am an NF, I do tend to focus a bit more on the emotional states of people than others may.... And I find INTP's to be total softies, though supercilious ones will usually point out your foolishness, which is embarassing and helpful.
They appear so different in some ways, and yet so similar in others...perhaps it's as if they are drawn to the same questions and yet go about the analyses very differently. I guess I just like thinking about this contrast.
What do you think about these two types compared to one another? Who would be better suited to answer this question, an INTP or INFP?