One of the first questions a teacher will have to face when designing a new course, particularly at the collegiate level, is whether to use a college textbook. College books offer two central advantages. First, textbooks arrange material in thematic units that can be helpful to instructors' lesson planning, especially for instructors early in their career. Instead of worrying how a larger subject ought to be broken down into a number of discrete units, instructors can simply follow the scheme already adopted in a textbook. This leads to the second central advantage college textbooks offer – namely, keeping students and instructors on the "same page. " There is never any doubt about where to go for the content relevant to the course – it is all (or nearly all) contained between the covers of the textbook. Naturally, not all courses will be amenable to being structured around textbooks. Liberal arts courses were typically less amenable than the hard sciences. But even that is changing at the college level, as more and more publishers craft textbooks designed to be used in courses that previously were built around a series of discrete readings. For example, a philosophy course on the problem of free will might, until recent years, have been structured around a series of key articles related to free will. But now it is very likely that an academic publisher has collected those key articles into a single volume, often times supplementing those articles with extra explanatory material. These volumes can be very useful for early-career instructors.
But textbooks are by no means mandatory. In the first place, there may simply not be a college book available for the course material or the textbook that is available might be outdated or objectionable for any number of reasons -- its expense not least of all. In such a case, instructors might well create a quasi-textbook of their own out of a group of discrete readings, as mentioned above. Many colleges and universities have in-house printing operations that will produce such quasi-textbooks – often known as "packets" – at an instructor's request. These printing operations, however, typically have a long lead-time so instructors must be diligent about collecting and redacting the relevant readings in a timely fashion. Moreover, instructors must be aware of their universities' copyright policies before they go about creating such a packet. Universities typically have a copyright officer who will examine a draft copy of the packet and make sure all the relevant permissions are secured.
Traditional Math Textbook
A traditional textbook is by no means the only choice for course materials!