This past week, I read T. Huston's Teaching What You Don't Know, largely on the recommendation of Anne Kelsch and her fantastic summer reading list. I spend a good bit of my career teaching courses that are at the absolute fringes of what I know. In fact, I am far more drawn to class that touches on at least some material outside my main field of study. It may sound perverse, but I spend plenty of time pondering the wonders of the ancient world; so I never feel particularly slighted if I don't have to talk about antiquity in each and every class that I teach. In an ordinary semester, I teach Western Civilization I, which begins and ends beyond the chronological limitation of my knowledge, The Historians Craft, which is part historical method and part historiography neither of which constitute a particular specialty of mine, and once a year I teach Graduate Historiography, which only touches briefly on any scholar who I have studied intensively. In short, most of my time is spent teaching what I don't know, if content is the main criteria by which teaching knowledge is evaluated.
As Huston points out, most of us end up teaching outside our area of specialty sometime during our academic careers. This is as much a reflection of the narrow scope of most graduate expertise as the nature of undergraduate curricula that tends to be equal parts conservative in the division of knowledge and cutting edge in the move to cross/trans/inter disciplinary research. For example, my Western Civilization class is a very traditional way of introducing students to European history which probably fits awkwardly with the methods, approaches, and concentrations most new history faculty experience in Graduate School. At the same time, the expanding influence of digital methods in history and the influence of social science and other disciplines with the humanities ensures a constantly revised body of post-structural/modern/colonial critique.
In some ways, we are always teaching what we don't know and, as a result, this book provides numerous helpful observations to manage the experience of teaching at the edge of understanding. While many of these are almost self-evident (e.g. read what you have assigned before the class begins... does this really count as advice?), some deal with how to manage student expectations. In history, it is always amazing to meet a student who is under the impression that we have taken the liberty of memorizing all of the primary sources. Managing student expectations is central to moving from the solid ground of content mastery (after all, I can list all the Roman Emperor and their dates of rule, can you?) to the far more marshy ground of teaching method or encouraging students to explore new approaches, analyze new texts, and imagine new problems.
It's hard to overstate the importance of these techniques in a field like history where teaching content is giving way to teaching method, the ability to teach what you don't know is all the more important. After all the real test of understanding comes only when a student confronts a foreign body of information and deploys successfully the techniques, methods, and approaches necessary to master it. While it remains easy enough to create "laboratory" type experiments for students where the instructor knows the possible outcomes and the students do not, these kind of teaching models almost always fall short of the risks inherent in real world research. As I tell my undergraduate historical methods class, when you pick a research topic in the real world, you are, to a very real extent, on your own to make sense of the material at your disposal. As an instructor, I can bring whatever knowledge of method and content to bear on the topic and material at hand, but there is no guarantee that I know the best way to approach a historical problem. As the infamous "banking" system of teaching where students master a set body of content gives way toward approaches that emphasize learning by doing (or other active learning type approaches) the possibility for teaching what you don't know increases massively. In fact, one could even argue that if you're not teaching what you don't know, then you're not doing it right.