Can learners use concordance feedbacks for writing errors?

This is a reflection written after reading my classmate 'Connie's Blog' about the use of concordnace feedbacks for writing errors. I think it is a great idea for having this kind of tool which allows learners to learn by themselves and retrieve authentic data base for their self-correction from the Internet. The tool has provided a one-stop solution for learners who would like to improve themselves. However, I believe the use of it would only be limited to a few types of learners:
1. Highly motivated learners who do not mind reading a lot and choosing the appropriate information from the retrieved data base for their own use (I doubt how many learners fall into this category!)
2. Learners with good English level (Otherwise, the concordance feedbacks are useless to them as they do not understand the retrieved data which is written in English.)
3. Professional writers, editors and language teachers
Then, what about low achievers? Anyway, it's difficult to invent a tool which can suit everybody's needs. Personally, I think it is very useful for my job as I can collect explanations from the Internet for my students' errors. I hope future developers of CALL could bear the low acheivers in their mind when inventing tools which are for their needs.