I don't think it was pretrained on knowledge gaps. A version was already available in testing w select customers. The version released to the public would definitely have feedback from those customers, and finetuned/instruction tuned on the data from ChatGPT.
Training data is publicly available internet (and accessible to everyone). It's the SFT step w high quality examples which determines how well a model is able to answer questions. ChatGPT's virality played a part in that in the sense that OAI got the real world examples + feedback others did not have. And yeah, it would have been logical to focus on 3.5's weaknesses too. From Karpathy's videos, it seems they hired a contractual labelling firm to generate q&a pairs.
Training data is publicly available internet (and accessible to everyone). It's the SFT step w high quality examples which determines how well a model is able to answer questions. ChatGPT's virality played a part in that in the sense that OAI got the real world examples + feedback others did not have. And yeah, it would have been logical to focus on 3.5's weaknesses too. From Karpathy's videos, it seems they hired a contractual labelling firm to generate q&a pairs.