ChatGPT Doesn’t Have a Database of Facts

It was trained to be believable, not to be right.
ai
ml
Author

Ken Arnold

Published

February 3, 2023

A colleague posted the following on our university Yammer:

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Here’s the text, for the search engines:

Factuality

  • The text saying “I have updated my information” was entirely vacuous; it has not actually updated anything. It has no readily-editable database of facts.
  • “I have updated my information” came from a human labeler who gave that answer as an appropriate response to a statement like that. (See Step 1 in the process diagram on the ChatGPT blog post.)
  • The human labeler probably intended that the engineers would actually implement some sort of update mechanism, but doing so in any general sense is an open research problem.

My colleague thought that he was helping correct a mistake in the model’s knowledge base so that it would represent our university better in its responses. But the model doesn’t have a knowledge base, no database of facts.

Truth vs Popularity

  • To the extent that ChatGPT has any conception of truth or fact, it defines factuality of a statement as proportional to popularity, or more precisely, how much of the Internet is consistent (in a very superficial sense) with it being true.
  • It is possible to extract a kind of knowledge base from the model after the fact1, but since the model does not store its knowledge as a set of assertions, there isn’t a straightforward way to update that knowledge base in general.
  • Human feedback during the training process can tweak it somewhat (which is partly continuing, based on people annotating your ChatGPT sessions, I hope you are ok with that!), but I doubt we’re going to see an improvement in the following output soon:

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  • me: What is the name of the Christian liberal arts school in Grand Rapids, Michigan?
  • ChatGPT: Calvin College is a Christian liberal arts school located in Grand Rapids, Michigan.

The general confusion of truth with popularity is not so readily dismissed.