Ok so the more I read the more complicated it gets.
This is what I've found:
- works best when the critical information is pointed out by an expert
- works best when model and self videos are not shown together
- works best when the information is understandable by the observer
- there is no significant difference between watching a model or oneself! :O
- it is helpful at all times, not just particular teaching stages
- it doesn't help with rhythm, coordination, and grace
- it can be a source of motivation
So my conclusion is that the key in the effectiveness of video is knowing what to look for. This could happen either through the voice of a coach/instructor, or through self knowledge of the skill.
In this contest, since most of the people posting are expert skiers, coaches, instructors, watching video WILL be beneficial. But it DOESN'T matter if the video is a WC skier or yourself!
This is the most shocking aspect to me! The idea is that video allows our brain to detect and correct errors, creating the "correct" motor patterns, unrelated to who is performing the action.
It remains that a beginner will not necessarily benefit from watching videos unless it is supported but someone with knowledge of the skill!
this is a review of most of the studies on the subject if you are interested
I think this is very much on the right track JZ. When you are skilled to a high level AND you are aware of the issues you need to correct (not always the case!!) then you are analyzing the video to see what you can translate.
I note also a very important difference between the comments by Marko and LF. Marko knew what he was looking for and wanted to apply what he had seen Adgate using to improve his times. LF has seen a motion/movement pattern Ted uses and wants to experiment with it to see if it will work for her. Very important (IMHO) difference.
Also, if you consider most race coaching. Yes, we use video, but most times on the hill, we will see an athlete doing something, point it out and get them to adjust WITHOUT seeing it. We can reinforce after by showing the video but the better athletes know enough to make the changes without having to watch it (me as Doofus of course doesn't necessarily fall into the better athlete category). Similarly, it is not that often a race coach will actually DEMONSTRATE something to an athlete during training, but relies on the high level understanding of the athlete to be able to understand and incorporate it.
This is not to say that watching videos is non productive, it can be very helpful in improving stoke, understanding what is possible etc. BUT to use it to drive self improvement works best if you are focussing on a couple of things and working on these. Just watching LV or MS make several excellent race runs is NOT, by itself going to make my race runs automatically faster. However, if I focus on a couple of areas where I KNOW i am losing time , then try to incorporate changes, I can make progress