When people outside the AI field hear about synthetic data for the first time, they often have one of two opposite intuitions. Either they assume that AI-generated data should be totally useless for training, or they imagine it should be possible to bootstrap all the way to superintelligence that way. Why neither intuition is correct is surprisingly subtle.
If the naive approach to synthetic data (i.e., just telling GPT-5 to generate a bunch of text and then training GPT-6 on it) worked, we would have general superintelligence already, much like the narrow superintelligence we have in board games like chess and Go. The problem is that, in order to be useful, training data has to encode information about patterns in the real world that the model doesn’t know yet. If the model doesn’t know those patterns yet, it can’t generally put them into synthetic data that it creates.
So the big challenge for AI labs is to figure out ingenious ways of making synthetic data work even when it seemingly shouldn’t. It’s sort of analogous to how aeronautical engineering isn’t antigravity—it’s all about finding clever ways of making heavier-than-air objects fly, even though a simplistic understanding of gravity suggests they can’t. In essence, generating useful synthetic data requires leveraging some kind of asymmetry between the information a model understands and the information content of what it can create. If the model knows enough to (with the right kind of highly specific engineering) put information in its outputs, but doesn’t yet deeply understand that information, training on those outputs can distill that information into a form the model can grasp more thoroughly.
One major asymmetry stems from the fact that it’s usually easier to verify the quality of outputs than to generate them. Another is that if a model spends a lot more compute on reasoning, it can act much smarter than its base-level capabilities allow. A third is that random exploration of potential solutions sometimes finds lucky insights. Together, these factors mean that it’s often feasible to have an AI produce a lot of data, curate the very best samples, and then train the next version on those. For example, mathematical proofs can be written in the Lean language, which lets them be cheaply and automatically verified. By scaling up test-time compute for reasoning quality and stochastically attempting many possible proof strategies, a model might generate 990 proof attempts that fail and 10 that succeed. The verifier system converts the winners into training signal that distills those insights back into the base model.
Humans experience something very similar with talk therapy or Socratic teaching. Sometimes you know things on some level, but can’t quite put them into words in a way that lets you reason about them. A skilled therapist or teacher can elicit that information from you. And then, when you hear what you just said in the session or the seminar (i.e., your synthetic data), you’re able to make better use of the insight that was hidden inside you. Once you have mastery over that insight, you may gain dim intuitions about harder questions that can subsequently be elicited to help you master those as well.
These analogies also suggest why synthetic data isn’t sufficient to create broadly superintelligent AI. Verbalizing ideas can help you crystallize vague insights that were already in your brain, but it can’t teach you brand-new information about the outside world. No Socratic professor can draw out of you the capital of Kyrgyzstan or the mass of the top quark if you haven’t first learned those facts independently. In the same way, synthetic data can help AI digest and master information, but training frontier-level models still requires ongoing contact with external reality.
Yes! I find most people pick up the right intuitions behind RL more easily than for synthetic data itself.