> There’s no technical reason you can’t back-track the weights and make a list of which tokens from which training data were sampled. The weights map inputs to

> There’s no technical reason you can’t back-track the weights and make a list of which tokens from which training data were sampled. The weights map inputs to outputs, not training samples to outputs. They are adjusted during the training phase and then kept fixed (until there's a new iteration of the model; and let's ignore online learning for simplicity's sake now, the major models we're talking about here don't use it afaik). From the perspective of a user who inputs prompts and receives answers, the weights are constant. We could create some score indicating how much each training sample contributed to the weights overall, but then that score would be the same for all prompts. It's really not clear to me what you mean by 'sampling from training data' for a specific prompt. The best I could imagine would be creating another metric measuring the distance between the prompt and all training samples, and then somehow combining that with the first score to get an overall contribution metric for this prompt. But that would be a) quite a bit of guesswork with a lot of modelling freedom and b) quite different from what you described.