I have tried to read the entire thread, but please forgive me if I missed any valid points. From what I have read I have drawn some conclusions and Iwill add myown opinion of some things.
Can a person learn a system form a video or book?
I have to give this one a huge yes.
It depends on a number of things:
the layout of the material,
There are people that can learn things from videos and books faster then an instructor can teach them and they look pretty darn good doing it. Ex, it seems that the IKCA guys are pretty good when I see them in competition and I think most of them had little if any face-to-face contact with an instructor.
But, IMO, the best the person will be able to do, will be to mimic what is shown. If the person watching the dvd has incorrect foot placement, moves on a slightly different angle, etc., there will be nobody to make corrections. This is akin to a white belt looking at the training guide for yellow, and trying to follow the techniques and katas by reading. That is all they have to go on, and sure, they can 'learn' from it, but its not designed to learn from, its a training aid. I've had people do just that, and then tell me that they know the tech. when I knew for a fact that they hadn't and it looked like crap, and now I had to take the time to make the corrections. Had they just waited, things would've moved quicker.
the depth of coverage of the material,
Some video series are better than others. My I-ryu instructor's instructor has a very good series out by Panther videos and it helped me tremendously with learning the I-ryu system.
Again, I go back to my TKD example. I don't do TKD. If I were to watch a Larry Tatum video, sure, I could probably learn a tech. or kata that I don't know and would probably stand a better chance, seeing that I do Kenpo. But, again, I'm only as good as what I'm watching. If I make a mistake, Larry Tatum isn't there to correct me. Now, if I were to pop the dvd in, and work the kata that I already knew, I'm not learning from the dvd, I'm using it as a reference. I've made my own tapes, during training sessions, but I'm using those, again, as a reference.
the person learning from the video,
Some people have a knack for learning from videos, they just happen to have a high visual accuity for video and book training. The students I have like this are great at visualization.
Still doesn't mean that they really are going to be proficient at making the material work.
do the have a person to make corrections,
I think we all agree that this helps with anything. Having someone that can look at their technique and fix the little things is always nice, but not always practical. Ex., I don't have a Kajukenbo school anywhere near me. So how can I learn a system when their is not one near? Its videos or nothing. As has been stated, it is easy to bash when you have 100 schools within a 1 hour drive. Here in KS, you are stuck with what you have(and most of the students I have drive further than 1 hour for instruction).
If it were a toss up of buying and learning from dvd, driving the 1 hour or making a trip to a real legit school, even if it meant extensive travel, I'd pick options 2 and 3. If someone wants something bad enough, they'd do what they had to do in order to learn properly. Of course, sometimes we must come to the realization, that learning X art may not be possible. I'd love to learn Kaju, but there're no schools around that I know of, in my area. My opions...don't train in it, find something comperable, move to a location that had a Kaju school, or perhaps take a weeks vac. time, fly to a school, train intensively, and keep working what I was taught. When time allowed, fly back and repeat the process. Won't be as productive as if I lived in the same state, but its better than trying to learn off a dvd.
Now, do I believe in the selling of rank? No Way, No How. But here are many schools that are belt factories. Ex., I had one "flex-trained" Kajukenbo BB come into one of my instructor's school and take classes for a while. Was he good, not really. But how can this be? He was "flex-trained." It happened for the same reason some of the video students make it to BB and are not very good. They sold him the rank. But that does not happen in schools, does it?
What do you mean by 'flex trained'? As for giving away, selling or anything else deceptive....I'm strongly against places like that.
My point I am trying to make is this, don't go crazy on somebody for trying to learn from a video or those trying to teach through a video series. They are doing the best they can with what they have. Feel free to kick the crap out of the people selling rank, including the ones selling through schools.
People are free to do as they choose. However, for someone to think that because they've made it thru Larry Tatums dvd set up thru 4th degree black, that in NO way does it make them a legit 4th degree BB. What it does make them, especially if they passed themselves off as one or tried to open a school, is a fake and fraud, and yes, I'd have no issues with telling them they were a fake either. Sorry, but I have to call 'em like I see 'em.