Posts ⁂ The Postmodern Terminal >_
Why the knowledge competent professionals carry in their hands counts as evidence, and why the evidence pyramid cannot rank it.
Ask a working professional how they know what they know, and watch them apologize. They will tell you about the study, the guideline, the framework they were taught; then, lowering their voice, they will mention the thing they actually do, the judgment they have earned over fifteen years, as though it were a guilty secret. I will argue that practice knowledge is evidence in its own right, not degraded theory, by showing how Donald Schön, Michael Eraut, and an old Aristotelian word together widen what a discipline is permitted to count, and by showing where the famous hierarchy of evidence stops being useful.
Schön gave us the sharpest picture of the problem. On the high, hard ground sit the well-formed problems that technique solves neatly: apply the established rule to the clearly defined case. Below that ground lie what he called the swampy lowlands, messy and indeterminate, where the situation itself is unclear and no textbook rule quite fits. Up on the high ground you apply a rule. Down in the swamp you exercise judgment. And Schön's line about the swamp is the one worth keeping:
the problems of greatest human concern
The professions have spent a century assuming the high ground holds the real knowledge and the swamp is merely where we apply it badly. That assumption is backwards. Theory explains; practice addresses. They answer different questions and correct each other, which makes them complementary rather than ranked.
Now the honest concession. The evidence-based practice tradition is not the enemy here, and you should know it well enough to use it. In its classic form from Sackett and colleagues, evidence-based practice integrates three things: the best available research evidence, the practitioner's own expertise, and the context and preferences of the people being served. Notice that the second element already smuggles practice knowledge in the front door. Expertise is evidence, by the tradition's own definition.
The hierarchy of evidence is where the trouble starts. The pyramid (expert opinion and case reports at the base, cohort studies above them, randomized trials near the top, systematic reviews at the peak) is a genuinely good instrument for ranking confidence about what works on average. It was built to answer effectiveness questions in clinical medicine. Many practice questions are not effectiveness questions at all. They ask how something is done well, why it transfers, what judgment it demands. Point the pyramid at those and a randomized trial can sit at the summit and tell you almost nothing. The hierarchy ranks evidence for one kind of question. Match it to the wrong question and it does not just fail; it silences the evidence you actually need.
So widen the category. Eraut shows that most professional know-how is acquired informally, on the job, and often stays tacit, hard to put into words and real anyway. Count only what reaches a journal and you miss the majority of what competent professionals know. Then there is phronesis, Aristotle's word for practical wisdom, the capacity to discern the right action in this particular situation. Barry Schwartz glosses it as moral will joined to moral skill and reaches for the jazz musician: know the rules so deeply that you can answer whatever the moment asks. Phronesis is the quarry. You are hunting for the wisdom that lets some practitioners get good outcomes across varied cases, and then trying to render that wisdom communicable enough that someone else can learn it.
One more turn before I let this go. Jürgen Kremer and R. Jackson-Paton's ethnoautobiography braids autobiography, ethnography, and participatory epistemology to ask a pointed question of the researcher: whose standard of "best" are you assuming? Your sense of excellent practice was formed somewhere, by someone, in some tradition, and it trained you to notice certain things and to overlook others. If practice knowledge is inseparable from the knower, then knowing yourself as a knower is part of the method, not a detour into confession.
Here is the concrete practice, then. The next time you watch someone do their work unusually well, do not applaud and move on. Write down what they did, in what setting, under what constraint, and what a rule would have gotten wrong. That note is data. Treat it as such.
The Postmodern Terminal >_