When determining if a book provides good coverage of a topic, readers are assessing the appropriateness of the content of the book.
if they are interested in the content of the book.
the appropriateness of the complexity of the book.
if they are selecting the book for the right purpose.

The appropriateness of the content of the book

either online or traditional classroom can work for students. which is better will depend on students and teacher. students may have trouble following a lesson in classroom while they can study at their own pace online. other students may have trouble staying focus on their own in online classes. teachers are more used to classroom teaching but they may also be more worry about their jobs teaching online classes and work harder.