LLMs understand nullability

The article puts scare quotes around "understand" etc. to try to head off critiques around the lack of precision or scientific language, but I think this is a really good example of where casual use of these terms can get pretty misleading.

Because code LLMs have been trained on the syntactic form of the program and not its execution, it's not correct — even if the correlation between variable annotations and requested completions was perfect (which it's not) — to say that the model "understands nullability", because nullability means that under execution the variable in question can become null, which is not a state that it's possible for a model trained only on a million programs' syntax to "understand". You could get the same result if e.g. "Optional" means that the variable becomes poisonous and checking "> 0" is eating it, and "!= None" is an antidote. Human programmers can understand nullability because they've hopefully run programs and understand the semantics of making something null.

The paper could use precise, scientific language (e.g. "the presence of nullable annotation tokens correlates to activation of vectors corresponding to, and emission of, null-check tokens with high precision and accuracy") which would help us understand what we can rely on the LLM to do and what we can't. But it seems like there is some subconscious incentive to muddy how people see these models in the hopes that we start ascribing things to them that they aren't capable of.

I was going to say "so you believe the LLM's don't have the capacity to understand" but then I realized that the precise language would be something like "the presence of photons in this human's retinas in patterns encoding statements about LLM's having understanding correlates to the activation of neuron signaling chains corresponding to, and emission of, muscle activations engaging keyboard switches, which produce patterns of 'no they don't' with high frequency."

The critiques of mental state applied to the LLM's are increasingly applicable to us biologicals, and that's the philosophical abyss we're staring down.

This only applies to people who understand how computers and computer programs work, because someone who doesn't externalize their thinking process would never ascribe human elements of consciousness to inanimate materials.

Certainly many ancient people worshiped celestial objects or crafted idols by their own hands and ascribed to them powers greater than themselves. That doesn't really help in the long run compared to taking personal responsibility for one's own actions and motives, the best interests of their tribe or community, and taking initiative to understand the underlying cause of mysterious phenomena.