Chapters — How AI Actually Thinks
LLM Fundamentals·Advanced·6 min read·Sep 5, 2026

Bigger Isn't Just Bigger

More dials, more training text, and more computing power tend to make a model better, but not automatically, and not without limits.

More practice usually helps

Someone who has read a thousand books generally has sharper instincts for language and ideas than someone who has read ten, all else being equal. That's a fair starting intuition for why bigger language models, ones with more parameters, trained on more text, using more computing power, tend to guess better than smaller ones.

But "all else being equal" is doing a lot of work in that sentence, and it's worth taking apart what's actually growing when people say a model got "bigger."

Three things that can each get bigger, separately

Parameters
The number of adjustable "dials" from earlier in this guide. More of them means more room to encode fine-grained patterns.
Training data
How much text the model was actually shown during training. More of it means more patterns to learn from, and more coverage of rare topics.
Compute
How much computing power and time was spent actually doing the training. More dials and more data both need proportionally more compute to actually put to use.

Turning up just one of these without the others tends to underdeliver. A model with an enormous number of dials but not nearly enough training text to meaningfully tune all of them ends up with a lot of dials sitting at close to their starting position, contributing little. The gains tend to come from scaling these together, roughly in balance.

Diminishing returns are real

Doubling a model's size doesn't double its usefulness. Early gains from scaling up tend to be dramatic: a model goes from barely coherent to genuinely useful. Later gains tend to be more incremental: a much larger, much more expensive model might handle a modestly harder set of tasks a bit more reliably, without the qualitative leap that earlier scaling produced.

This matters because it means "make it bigger" isn't a free path to fixing every weakness. A vastly larger model built the same way, on the same kind of data, will still fundamentally be a guessing machine, still without a built-in fact-checker, still limited by whatever context window it's given. Scale sharpens the guessing. It doesn't change what kind of thing is doing the guessing.

Why quality of training data matters as much as quantity

A student who reads a thousand books gains more from a thousand well-chosen, varied books than from the same book copied a thousand times. The same principle applies here: a larger amount of repetitive or low-quality text doesn't teach a model nearly as much as a smaller amount of varied, high-quality text would. Scale and quality are separate levers, and both matter.

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How AI Actually Thinks

A first-principles guide to what's really happening inside a large language model, built from simple analogies up to the real mechanics.

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