While it is not necessary to use unit contracts for this purpose, structuring a course in this way is a powerful tool for rethinking academic priorities and reshaping the course accordingly.  Here are some tips on how to do that.

Plan backwards for the whole course

Start with the fundamental question “What should my students know and be able to do when they are finished with this course?”  Answering that question in detail can be a surprisingly difficult task, and is best shared with colleagues who teach the same course.  In any case, it is an essential step in consciously planning the scope of every unit.

Many teachers emphasize the topics at the start of the year to the depth that they think is needed.  By the time spring rolls around (or the end of the semester, if there is a standardized semester exam), they realize that there is not enough time for the remaining units;  they are forced to reduce the depth of the remaining units, squeeze the units into a shorter time span, and/or eliminate whole topics altogether. These decisions are often frustrating, even painful.  

A better alternative is to start by prioritizing the learning goals for the entire course, designing the whole year’s curriculum in broad strokes, and working backwards to decide how deeply each topic will be treated.  In so doing, you will also be deciding what units are more important and deserving of emphasis. The use of unit contracts offers a platform to organize this design process.

Define the purpose and scope of each contract

Design the content of each contract around a single coherent theme.  For example, over time I found that teaching Newton’s three laws of force required creating five different contracts: the Law of Inertia, the study of the forces acting on a body at rest, the study of the forces acting on a body that is accelerating, the conceptual implications of the equation F = ma, and the Law of Action and Reaction.  The first, fourth and fifth contracts evolved into strictly conceptual units, while the second and third were exclusively about the development of mathematical skills. A different teacher might well design this sprawling topic in a very different way and be equally effective.

Don’t follow the book

It is essential that the scope of a contract be determined by the learning process, not by the chapters in the textbook.  If you have a brilliantly designed textbook, chapters and contracts may, in fact, coincide, but optimizing the experience of the student should always drive the design of the contract.