The capstone assignment is your opportunity to think concretely about what students ought to be able to do at the conclusion of your course that they couldn't do (or couldn't do as well) at the start. This may be done after setting your course goals, or designing the capstone assignment may provide the opportunity to clarify and refine your course goals and objectives.1 We recommend first considering what mastery looks like "in the wild"—what does it look like when a CEO does that thing well? What does it sound like when you overhear a professional talking about that subject at the conference bar? From there you can consider how that mastery can be simulated "in captivity" in the classroom.
A capstone is a summative assessment, and as such it should provide opportunities to synthesize large amounts of content and/or skills and to engage with course material creatively (if not quite in the popular sense of artistic creativity, then at least in the academic sense of creating one's own argument about a particular field of knowledge). In designing a cumulative, synthetic, or synoptic exam or final project, you should think carefully about what kind of mastery you are assessing, and about how best to ask your students to demonstrate it.
If you have read our page on taxonomies of learning, you will know that different "assignment verbs" correlate to different levels of sophistication. Asking students to "list" the causes of the French Revolution, for example, is a relatively low-order question: in essence, you are asking students to remember what someone else has told them about French history. So, too, is asking students to "recognize" something. On the other hand, "analyze," "apply," "evaluate," and "create" represent higher-order tasks: the students must take what they have been taught and use it to perform a new action, with varying degrees of self-awareness and disciplinary sophistication as they do it. Any of these kinds of verbs could be appropriate at some point in a summative assessment—the key thing is to make sure that you are not asking students merely to "remember" a concept that was crucial to the class, and with which they ought to be able to do much more; or to "evaluate" something that was more tangential to the course, and for which simple recall would be a sufficient measure.
Some Common Genres of Capstone Assignments
In addition to the content of the assignment, the form matters as well. Some of the most familiar types of summative assessment are exams and term papers. However, the best capstone assignments are those that are created after careful consideration of the goals and objectives of the course. For instance, if you want to measure students' ability to retain and recall content from the course, or whether they've read the assigned readings, an exam is a great tool. And if you want to measure students' ability to locate and synthesize secondary materials in support of a research question, a term paper is perhaps the ideal option. But if you hope to have students test one or more academic claims against what those claims allow them to do in the world—or, perhaps, to encourage your students to become translators and ambassadors—you will want a capstone that connects their academic learning to the wider world through acts of community engagement and/or public teaching, such as a poster presentation or gallery installation. Assigning a creative or "non-traditional" assignment can require extra preparation (which we explain here) but they can be more effective tools for student learning.2 Often they are designed in such a way that students receive feedback from multiple sources—their peers, an audience—in addition to the instructor.