I've changed the professor's way just because I'm sloppy. It is a bit of a pain to take a script out of my bookshelf or computer. Perhaps, it might be better to look at them more often.

I've been using this method for about two months, but I don't follow exactly what the professor who thought of shadowing says. I basically repeat easy materials without the scripts, and I look at them just a few times. Shadowing seems to be improving my listening, speaking, and reading skills. It still takes some time for me to understand English sentences even though they are very easy, but I can understand more quickly than before. If someone asked me for some suggestions about learning languages, I would definitely recommend this method.

I think if you're really devoted to it, it would be very effective. It's a bit hard to come across facing translation books in bookstores, and audiobooks in certain languages are hard to come by, but if you have the resources and the time I think it would be a powerful technique. I have no prior experience with it, but I have studied how people learn and Shadowing creates a holistic, gestalt learning experience which one fully embodies. The "walk briskly in nature" step should be integral to the process, though