Re: advantages and disaadvantages of on-line learning
Please don't file them away with the learn English in 30 days Car Audio CDs. They have their limitations, but they are surely in a higher league than that.
The advantages are learning at your own pace and getting a customised program. Also, in a book, a student typically does 10 questions on a language point and then waits for a correction. In an online context, we can use a databank of several hundred questions so that the student can work through until really competent in that area.
The obvious weaknesses are in speaking and writing, but these too can be overcome through technology - voice recognition and also programs that can grade written work.
The other thing is social context. Computers are years away from being able to react in a socially normal way with a human. This, of course, is a big part of an ESL course.
Many companies offer 'blended' courses to the corporate market which make use of the advantages of both styles of learning - online and 'face to face'.