On 3/19/2013 4:57 PM, David C. Ullrich wrote: > On Tue, 19 Mar 2013 08:38:20 -0700 (PDT), firstname.lastname@example.org wrote: > >> On Tuesday, March 19, 2013 3:26:49 PM UTC, Frederick Williams wrote: >>> quasi wrote: >>> >>> >>> >>>> >>> >>>> Yes, but the best teachers and authors have mastered the art of >>> >>>> judging how their presentation would be seen from the point of >>> >>>> view of the prospective student. >>> >>> >>> >>> While the lecturer knows to whom he is lecturing, the author of a book >>> >>> doesn't necessarily know who will read it. >>> >>> >> This seems exactly the wrong way round. A good maths book will specify exactly what the readership is expected to know -- "prerequisites" in other words. >> On the other hand, the abilities and knowledge bases of a graduate and undergraduate class can vary enormously, and it is difficult (but not impossible) to find out what they know. > > > ??? There are _official_ prerequisites for a class. A student is not > _allowed_ to take this class without having passed those other > classes. All the author of a book can do is explain what audience > he had in mind - he has no control over who actually reads the book. > > What's difficult about finding out what the students know? > After the first quiz in differential equations I can tell you > which ones know enough calculus. > > Your, erm, experience must be vastly different from mine; > in particular the rules and regulations at the place where > you teach must be very different. > > "exactly the wrong way round" indeed. >
Some, like myself, study outside of the guidance of curriculum committees and without the help of instructors.
I visit used book stores seeking books I can afford -- some beyond my skill level.
I work at understanding what I can. I look for books that fill gaps when I have purchased beyond my abilities.
So, I do appreciate when an author makes a plain statement of prerequisites.
Even so, any book is better than no book when one is interested.