“In discussions about different language-teaching methods and philosophies, it is sometimes said that it is not so much the methods-or even the teaching materials-that matter, so much as what the teacher does with them. While this is perhaps stating things a little strongly, few would doubt the basic importance of the teacher’s ability and attitude: ability because materials need expert help if they are to realize their potential, and attitude because there is no better way to ensure a flop than to go into class expecting one. The teacher, clearly, is a crucial element in the success or failure of a lesson.
Although this is taken for granted in the field of language teaching in general, the same perception is less often extended to materials used in computer-assisted language learning. Language-learning computer programs, to a much greater extent than language-learning materials on paper, are expected to stand or fall on their own merits, without consideration of their role in a classroom lesson.” (Jones 1986: 171) Also quoted in Chappelle 2001 and Blake 2008.
It is also risky to compare online materials and face to face teaching. If you want to do that, you will need an equal number of hours on task and similar skills on focus (i.e. oral interaction).