Textbook manifesto by Allen B. Downey.
From the post:
My textbook manifesto is so simple it sounds stupid. Here it is:
Students should read and understand textbooks.
That’s it. It’s hard to imagine that anyone would disagree, but here’s the part I find infuriating: the vast majority of textbook authors, publishers, professors and students behave as if they do not expect students to read or understand textbooks.
Here’s how it works. Most textbook authors sit down with the goal writing the bible of their field. Since it is meant to be authoritative, they usually stick to well-established ideas and avoid opinion and controversy. The result is a book with no personality.
For publishers, the primary virtue is coverage. They want books that can be used for many classes, so they encourage authors to include all the material for all possible classes. The result is a 1000-page book with no personality.
… (emphasis in original)
You probably know Downey from his Think Python, Think Bayes books.
Think Python, with the index, front matter, etc. runs 244 pages from tip to tail.
Longer than his proposed 10 pages per week for a semester course, total pages of 140 pages for a class, but not unreasonably so.
Take this as encouragement that a useful book need not be comprehensive, just effectively communicating more than the reader knows already.