An ill-advised blog post in which I speculate that academia is actually for-profit, but not in the usual sense of “profit”.

What is a model, particularly of a programming language? I’ve been struggling with this question a bit for some time. The word “model” is used a lot in my research area, and although I have successfully (by some metrics) read papers whose topic is models, used other peoples’ research on models, built models, and trained others to do all of this, I don’t really understand what a model is.

Before I get into a philosophical digression on what it even means to understand something, let’s ignore all that and try to discover what a model is from first principles.

I’m in the middle of confronting my lack of knowledge about denotational semantics. One of the things that has confused me for so long about denotational semantics, which I didn’t even realize was confusing me, was the use of the word “syntax” (and, consequently, “semantics”).

For context, the contents of this note will be obvious to perhaps half of programming languages (PL) researchers. Perhaps half enter PL through math. That is not how I entered PL. I entered PL through software engineering. I was very interested in building beautiful software and systems; I still am. Until recently, I ran my own cloud infrastructure—mail, calendars, reminders, contacts, file syncing, remote git syncing. I still run some of it. I run secondary spam filtering over university email for people in my department, because out department’s email system is garbage. I am way better at building systems and writing software than math, but I’m interested in PL and logic and math nonetheless. Unfortunately, I lack lot of background and constantly struggle with a huge part, perhaps half, of PL research. The most advanced math course I took was Calculus 1. (well, I took a graduate recursion theory course too, but I think I passed that course because it was a grad course, not because I did well.)

So when I hear “syntax”, I think “oh sure. I know what that is. It’s the grammar of a programming language. The string, or more often the tree structure, used to represent the program text.”. And that led me to misunderstand half of programming languages research.

I’ve been trying to understand the semantics of memory in WebAssembly, and realized the “memory safety” doesn’t mean what I expect in WebAssembly.

I have long struggled to understand what a logical relation is. This may come as a surprise, since I have used logical relations a bunch in my research, apparently successfully. I am not afraid to admit that despite that success, I didn’t really know what I was doing—I’m just good at pattern recognition and replication. I’m basically a machine learning algorithm.

So I finally decided to dive deep and figure it out: what is a logical relation?

As with my previous note on realizability, this is a copy of my personal notebook on the subject, which is NOT AUTHORITATIVE, but maybe it will help you.

I recently decided to confront the fact that I didn’t know what “realizability” meant. I see it in programming languages papers from time to time, and could see little rhyme or reason to how it was used. Any time I tried to look it up, I got some nonsense about constructive mathematics and Heyting arithmetic, which I also knew nothing about, and gave up.

This blog post is basically a copy of my personal notebook on the subject, which is NOT AUTHORITATIVE, but maybe it will help you.

I have argued about the definition of “ANF” many times. I have looked at the history and origins, and studied the translation, and spoken to the authors. And yet people insist I’m “quacking” because I insist that “ANF” means “A-normal form”, where the “A” only means “A”.

Here, I write down the best version of my perspective so far, so I can just point people to it.

I’ve been doing, and experiencing, a lot of peer reviewing lately. I’ve been ranting about it on Twitter as I get reviews that don’t help me and, in many ways, hurt me, and lauding reviews that provide useful constructive feedback (even if I disagree with it or the decisions). I’ve been trying to figure out how to provide good reviews and avoid negative aspects of reviewing.

I need to get the thoughts out of my head. These are not declarations of what peer reviewing is or should be, but my attempt to work through those questions.

I wrote the follow at some semester prior to today, about no one in particular, while updating syllabus.

It’s weird, but professors are almost never taught how to teach, how to design a course, how to assess students, how to design an exam or what the point of an exam even is. We’re just expected to pick this up on our own, I guess. It’s not as nonsensical as it sounds, since we are trained how to do research and communicate that research, and there is some overlap. But still.

If my experience is any indication, we just pick up an existing course structure and more or less follow that. Oh, the last person who taught this course used this material, and this syllabus, and these exams, so I’ll just do more or less that for now. If we’re ambitious and/or want to shoot our tenure track in the foot, we might try to innovate soon after. Otherwise, we might innovate later.

Anyway I’m not good at doing things just because that’s how they’ve always been done; I need first principles. After designing, administering, grading, invigilating several of them, I was struggling to figure out what the point of a final exam is. So I had a bunch of conversations on Twitter and now I’m collecting my thoughts on what the point of a final exam is and how it might, or might not, serve a purpose in my course.

Warning: I am not an education researcher, and this is not research, and it’s got a lot of stream-of-consciousness.