Kata Purpose

 Every Eastern Defensive system being taught in the West utilizes their own version of the kata that were taught in Okinawa (some via Japan) and/or China. There seems to be a lot of concern as to where each kata originated, and where  it was (if it was) changed/modified. 
 Oyata was familiar with numerous kata that were being taught at the time of his own research (after his 2 instructors passed on). He had sought the most original form of those kata that he was able to locate. Many of the original/older instructors had died during the time of the second world war, this meant that he in many ways, had to "settle" (?) for what remained available to him to learn. 
 Of the numerous kata (that he learned) he choose 12 to teach in his system. He felt that these kata provided his students with the greatest range of  motions/examples (technique?) for his students study/research. 
 The (2) kata that he had been shown/taught originally (by his two instructors) had been explained to him and the method of "breaking down" (interpreting) those kata is what he used to decipher the kata that he learned afterword. 
 He (Oyata) explained to us (his students) that each movement/motion performed within the kata served a purpose. Beyond the formality of the "bow", every motion should reflect an applicable purpose for "Life Protection". That didn't always imply a "technique". Some motions and positions were a display of a "principle" (for application and/or protection). 
 In his own words, he stated that kata was not for learning how to (publicly) display one's knowledge and/or ability (I.E. "spar"). It was a reference for the individual techniques that are utilized for Life Protection. There is no need to be able to "spar" for minutes on end, a (true) Protection technique only requires seconds to utilize (and the confrontation should be ended). 
 (According to Oyata) The techniques displayed in the kata motions, are of varying levels (of interpretation). The most "obvious" are those that anyone could see/understand. The next group of techniques were those that only students who had practiced the motions would discover. The last were those that would only became apparent to those with the experience of being involved in confrontations would recognize.   
 Aside from being a little vague, the point was that a student had to study the kata in order to decipher the motions. The majority of interpretations that are presented on the internet (if not in "seminars") fall into the first category. 
 Oyata's explanation did not define a "one technique, for every motion". It was a multiple techniques and definitions for every motion performed in the kata. 
 This required the student to research as to whether the (every) motion performed was the forward or reverse version? (of what it was demonstrating). Was the motion that of the tori? or the uke? Was the motion (only) the important part of an application/motion? or that of an aggressor? Was it a "striking" defensive/offensive motion (as well as who's it represented, tori/uke?). Was it an example of a commonly made motion (be it aggressive or defensive). 
 When approached in this manner, the study of a kata should require years of research/practice. Oyata (often) stated that each student will find "1" kata, that they are most comfortable with.  Everyone is different, so he provide us with an assortment of kata that he felt would (each) provide similar opportunities for discovery of that individual "comfort" kata for varying students. 
 When a student has found their kata, that student should practice that kata repeatedly (over years). Every motion will become second nature (without thought) and those motions will become that students defensive motions. 
 While in class, that student should examine the motions of that kata in every defensive situation that they can imagine, or be presented with. They should examine the use/application of every motion within that kata and determine which motions should be utilized in which situation(s). 
 The purpose of an instructor (in a research situation) is to either validate/invalidate a student's use of a motion, or to help them to refine that motion (to be more practical/effective). 
 This is not a practice reserved for "Black Belts", a new student should be experimenting with this as well. That's the purpose of being in a class, to learn, question and experience the application of what's being shown to you. This can't occur with those "student's" who believe that they can only engage in "solo" practice (alone). There has to be interaction  between two (and preferably more) students. All must be fully aware of what they are practicing, and willing to question how/what they are being shown. 
 The greater the variance in (practice) partners, the better. Being able to dominate (only) a (single? two, three, five?) fellow classmate(s), is not the best manner to determine one's ability (or lack thereof).