donald knuth

Autumn Christian ✓ @teachrobotslove The computer scientist Donald Knuth talks about how he figured out he could use randomization for qualitative problems, like grading his student papers, in "Things a Scientist Rarely Talks About." [Image: book excerpt text] Such techniques are clearly a win for quantitative problems, but I began to use randomization also for qualitative things. For example, when teaching at Stanford, I often used randomization when I was grading papers. (Yes, I'm sure students sort of suspected this all the time.) Let me explain why I'm not ashamed to admit the fact. Suppose a student has presented me with a 200-page listing of a computer program — a term project, say — and I don't have time to read all 200 pages. So I turn to a random page and I look very closely at what's on that page; what I find there suggests other pages that I should look at. (The program might invoke a subroutine, for instance.) The parts I do look at, I check over very carefully; for example, maybe I'll have to check out what that subroutine does. But I don't have to read all 200 pages. And the student doesn't know what pages I'm going to look at. So I can get a pretty good idea about the quality of the program by using this approach. And in fact, all kinds of theories have recently been developed about things like "zero knowledge proofs" by which people can convince you that they know how to solve a problem without revealing how they do it. Randomization has therefore turned out to be useful in ways we didn't expect at all. 5:34 AM · Feb 23, 2026 · 22.6K Views