well, from my limited experience as an instructor, some of my students "learned" some "techniques" online, and most of it is off... not sure if they "learned" about it from a forum or from a website, but really one can't learn well something they have little or no experience in, just by reading someone's post. even an excellent and outstanding martial artist with vast experience, couldn't clearly detail how to do a technique easily, let alone most people who post and share knowledge like the majority of us.
Some can do very well via video, such as chinaboxer, but you can see the points made on the video have been well thought out on how to present it and the topic discussed is narrow, any more info and it will be too difficult to answer every aspect or question that may arise. so a good video or post will be right on the topic, well thought out, and not leave room for if's and's or but's, and it won't try to overwhelm a reader/viewer with info.
When I first started my blog, I was thinking of putting a "techniques" section on there, however, after seeing how my students understood stuff they learned online I realized that it would only hamper other's progress in their own arts and make things difficult for their teachers.
So there's nothing wrong with reading stuff online, but when we put an "instructional/how to" post or reply to a person's how to question, we should really consider to speak clearly and accurately and it is helpful to know the approximate level of understanding of the person asking the questions so as to speak in a way they can comprehend accordingly.
I think the purpose of this thread is to let us all have some thought about how we post and share so we can have a better growing community. put more heart to how we post to make sure it is clearly understood.