The engine and the car

The whole large language model space is brand new, and there are lots of folks trying to make sense of it. If you’re one of those folks, here’s an analogy that might come handy.

Any gasoline-powered car has an engine. This engine is typically something we refer to as a “V8” or “an inline 4” or sometimes even a “Wankel Rotary Engine”. Engines are super-cool. There are many engine geeks out there – so many that they warrant a video game written for them.

However, engines aren’t cars. Cars are much more than their engines. Though engines are definitely at the heart of every engine, cars have many additional systems around them: fuel, electrical, steering, etc. Not to mention safety features to protect the passengers and the driver, and a whole set of comforts that we enjoy in a modern car. Pressing a button to roll down a window is not something that is done by the engine, but it’s definitely part of the whole car experience.

When we talk about this generation of AI systems, we typically talk about large language models (LLMs). In our analogies, LLMs are like engines. They are amazing! They are able to generate text by making inferences from the massive parametric memory accrued through training over a massive corpus of information.

However, they aren’t cars. One of the most common mistakes that I see being made is confusing engines (LLMs) with cars (LLM-based products). This is so common that even people who work on those products sometimes miss the distinction.

When I talk to the users of the PaLM API, I see this confusion show up frequently in this manner: developers want to reproduce results from the LLM-based products like Bard or ChatGPT . When they try to get the same results from the API, they are disappointed that they don’t match. Factuality is lacking, API can’t go to the internet and fetch an article, etc. 

In doing so, they confuse the engine with the car: the API, which offers access to the model, is not the same as the products built with it. With an LLM API, we have a big-block V8. To make it go down the road, we still need to build the car around it.

 To build on this analogy, we live in the early age of cars: the engines still figure prominently in the appearance and daily experience of a vehicle. We still have to turn the crank to start the car, oil the engine frequently, and be savvy enough to fix minor problems that will definitely arise.

As our cars become more refined, the engines get relegated into a well-insulated compartment. Users of cars rarely see them or operate on them directly.

This is already happening with LLM-based products. Very few current offerings that you might encounter in public use are LLMs that are directly exposed to the user.

So, when you use a chat-based system, please be aware that this is a car, not the engine. It’s a tangle of various AI patterns that are carefully orchestrated to work as one coherent product. There is likely a reasoning pattern at the front, which relies on an LLM to understand the question and find the right tool to answer it. There is likely a growing collection of such tools – each an AI pattern in itself. There are likely some bits for making sure the results are factual, grounded in sources, and safe.

As the LLM products become more refined, the actual value niches for LLMs become more and more recognizable. Instead of thinking of one large LLM that does everything, we might be seeing specialization: LLMs that are purpose-designed for reasoning, narration, classification, code completion, etc. Each might not be super-interesting in itself, but make a lot of sense in the overall car of an LLM-based product.

Perhaps unsurprisingly, the next generation of cars might not even have the same kind of engine. While the window control buttons and the steering systems remain the same, the lofty gasoline engines are being replaced with electric motors that fit into a fraction of space. The car experience remains more or less the same (aside from the annoying/exhilarating engine noise), but the source of locomotion changes entirely.

It is possible that something like this will happen with LLMs and LLM-based products as well. The new open space that was created by LLMs will be reshaped – perhaps multiple times! – as we discover how the actual products are used. 

Leave a Reply

%d bloggers like this: