Well in karate kata is pre-arrange movements involving only one person.
I was always told by my sensei that's what you call kata.In my times as a martial artist,I have seen even in tournaments people always doing one man forms which they were calling katas.I've never heard of a two man kata.
If there are katas involving two people how come in the 12yrs. of my karate experience and going to tournaments,I have never seen a man do kata that was not done on his own.
While I do pankration at the moment where every thing involves two people practicing techniques (which are impossible to do without a partner )and putting them to use in sparring,no one ever calls them katas and if you asked my current school if they do forms they would say "No".
If you told them they did forms because the techniques look pre-arranged they would probably laugh and why?
Well our techniques can go from one movement and quickly changed into another technique right away(in whatever we think might work at that particular moment) when the first one doesn't work on some one,where as in each kata the techniques are always done in same order,never switching in to another movement that wasn't put there.Katas don't allow you to be creative they train you to act in the order you were taught.
A kata can be of some use to an extent if a person can be creative enough to think on his own how to go from one to another instead of going from moves to others in the order being taught.
Ex. punch to kick,who says it's always going to be in that order.
My point is not only are katas pre-arranged they do not use a partner to practice on which makes it difficult to be creative and understanding of how to change technique to technique without always having to rely on something happening the same way at same time.
If katas involved two people they can't possibly be pre-arranged at least not with contact anyways.
Don't get me wrong I'm not saying you're ignorant of martial arts,all I am saying is that in my experience that is what I've been taught and seen and you have obviously been missinformed.
Don't take it personal.I'm not here to put anyone down just to give opinions and help people understand if necessary since I've studied two traditional arts and now one that's different from most traditional schools as we training specifically for self-defense or some may call street defense.
check out my style pankration at: http://mypage.goplay.com/asoka4