I guess a question to ask is "What is GPT-4". Is it the algorithm, the weights, the data, or a combination of them all? To put it another way, the researchers

I guess a question to ask is "What is GPT-4". Is it the algorithm, the weights, the data, or a combination of them all? To put it another way, the researchers at Rad AI consumed every paper that was out there including very cutting edge stuff. This included reimplimenting GPT-2 in house, as well as many other systems. However, we didn't have the same data that was used by OpenAI. We also didn't have their hyperparameters (and since our data was different it's not a guarantee that those would have been the best ones anyways). So with that in mind it's possible that Rad AI could today be using their own in house GPT-4, but specialized with their radiology data. In other words them using a specialized model, and them using GPT-4, wouldn't be contradictory. I do want to toss out a disclaimer that I left there in 2021, so I have no insights into their current setup other than what's publicly released. However I have no reason to believe they aren't still doing cutting edge work and building out custom stuff taking advantage of the latest papers and techniques.