I’ve been contemplating this situation. I think that what the author wants out of a Jev-like model is not at all what I want out of it.

> I decided to check this on questions where the answer is well understood. For example:

> A classical particle of mass m is embedded in a system at thermodynamic equilibrium with temperature T. What is its velocity v?

If I feed that into a model, the answer I want is: “the combination of the model and the provided state has nothing useful to add to your prior”.

If I want to know the Maxwell-Boltzmann distribution, I can look it up or I can derive it or I can ask a fancy LLM to do it for me (at the cost of some reasoning tokens and some time - unless I’m using an ultraspeed inference system, I’m not getting this answer in 50ms). [0]

Similarly, if I want to know that 73% of incoming customer support requests are spam/fraud, I should measure that - it’s a property of my system, it takes some manual classification and a database query, and it will be a different percentage than your customer support system would see. I neither expect nor want my classifier to know this (unless I’m using a conventional classifier manually trained on my data, and the whole point of Jev is to avoid this).

What I want out of a system like Jev is to tell me how the probabilities change as a result of the per-sample data I provide. Which, is the case of this Boltzmann distribution question, is nothing: I provided no data and the classifier can infer nothing.

[0] A really good answer would observe that the answer depends on the dimension of the system (probably 3, but 2D systems are a thing) and also on whether the particles are hot enough for relativistic effects to matter (probably not). And maybe a good answer would check whether the material is a gas - the answer for a solid is not the same, but I suppose that’s not classical. Oh, and one shouldn’t forget drift: if you have a classical particle in a moving fluid or a classical charged particle in an electric field, you will again get a different answer.

Yes, I’m being pedantic. But if you want good answers you should be pedantic, and the Jev-like model is not where the pedantry should go.

How accurately calibrated is Jev?