The Art of Leaving Stuff Out (Ep. 15)

It's hard to leave stuff out. But it's a key part of passing on knowledge.

Mar 25, 2024

Let me start with a quote:

It’s much easier to write a 3,000‐page introductory textbook than a 300‐page one. But I believe a 300‐page one is more useful.

Full disclosure: I'm quoting myself. I wrote this in the final thoughts of the Python programming textbook I just published. I'm telling you all this for two reasons:

It's an excuse to plug my new book.
Writing the book made me think about and appreciate more the point I want to share in this post.

A key skill for an educator is knowing what not to say, what to leave out when teaching. Or writing a technical article.

But surely, more is better, no? • No.

Let's start with a "proof" of this. I plan to teach my son how to prepare scrambled eggs. Here are two scenarios:

Here are three eggs. Scramble them.
Beating eggs denatures the proteins within them. Proteins are long chains of amino acids that unravel and elongate when denatured. This process exposes amino acids that repel water (hydrophobic) and attract water (hydrophilic). As the egg whites are beaten, these proteins uncurl and stretch out, forming structures that trap air bubbles, resulting in a lighter texture. The physical act of beating causes the protein strands to stretch and denature, allowing for the formation of a solid mass from a liquid solution of protein.
When eggs are scrambled, the protein structure undergoes denaturation and coagulation due to the application of heat. The proteins in eggs, primarily ovalbumin, unfold and loosen from their folded structures when exposed to heat. As heat is applied, these proteins collide and form a 3D web, transitioning the egg into a semi-solid state. The denatured proteins expose their hydrophobic and hydrophilic ends, creating a network that traps air bubbles and water, resulting in the formation of scrambled eggs.
It's important to note that egg whites and yolks coagulate at different temperatures, with egg whites starting to coagulate at around 60°C (140°F) and yolks requiring slightly warmer temperatures. By understanding this process, one can achieve the desired texture of scrambled eggs by controlling factors like the addition of liquids, cooking temperature, stirring technique, and timing to ensure a fluffy and creamy outcome.

Scenario 1 clearly provides too little information for someone who's starting from no knowledge of how to cook scrambled eggs.

Scenario 2 clearly provides too much information for the same person.

The ideal amount of information is somewhere in between these two.

Ergo, more is not better.

Scenario 2 generated by Perplexity AI. Life's too short for me to research this and write it myself. If your scrambled eggs are ruined, blame AI.

Cognitive load, working memory, and all that • Let's say we could categorise the stuff you need to understand about a certain topic into 10 stages. And you're a complete novice. You can't learn stages 1 to 10 simultaneously. That's fairly clear.

But there's also a delay between each stage. Each stage needs time "to brew", and the successive stage will only truly make sense when the previous one is well understood. These are those "Aha!" moments when a topic clicks in place.

Present too many stages to a beginner, and not only will the later stages be hard to understand, but they'll impact how efficiently the earlier stages are understood.

300-pages instead of 3,000 • Did I tell you already I published a textbook? Yes, I think I may have. I spent so much time and effort deciding what not to include–not because I didn't want to write more (in fact I already wrote most of the "extra" stuff I didn't include), but because I think the result is better for my intended audience.

Afterword • There's so much more I'd like to say about this topic. But I won't. Not yet.