[gravity13]

I've actually been thinking about doing the same thing in a side project of my own, and while I think you're somewhat correct, I don't think this is all necessarily attributable to affinities for symmetry.

For instance, if you convey a concept, and then show the derivation of the equation for that - the derivation mostly does not matter in the communication of the concept. Sure it's important to understand this, thus why we always have the derivation, but often it adds cognitive weight that distracts from the more germane understanding of the material (so keen authors will try and be elegant about the complicated things, skipping steps and keeping as much on one page).

It takes up cognitive load, and often a different type of load than the big picture. By collapsing the content, you get back to the more pure "short version" of the material and you can presume to understand or trust the more complicated bits that are hidden away.

[StavrosK]

I see what you mean, but why does it matter? By the time you've read the explanation, you've moved past it, and no additional action is necessary, it's just of no interest to you any more, like the rest of the text you've read. Adding a collapsing mechanic would "require" you to take action again by collapsing the thing, even though you will never return to see it.

[IanCal]

There are a few things:

Even if it's not that useful, it's what I expect to happen without thinking. Having no "undo" makes me wonder what happened and a vague fear that I've done something destructive. More personally, it just feels a bit weird with the way I jump back and forth in documents as everything moves. I can't quite explain it but it feels quite weird.

> By the time you've read the explanation, you've moved past it

The explanations/diagrams don't appear immediately after/over what I click. So I click for extra info, jump over some intermediate text and read the extra stuff then I want to go back to the normal flow. Look at 'atoms' and 'photons' in the example text: https://skorokithakis.github.io/expounder/

There are other examples of this too, in your original blog post about building the sensor. Look for examples where the extra explanatory text appears in a paragraph after what you click on.

[StavrosK]

> I can't quite explain it but it feels quite weird.

I definitely know what you mean, but it's a problem with me being compulsive about having opened things stay open, not with the things themselves :P

> So I click for extra info, jump over some intermediate text and read the extra stuff then I want to go back to the normal flow.

I think that's the best argument so far. However, I think this is the "footnote" mindset (i.e. you go look up what the footnote is and come back). Expounder works under a more integrated mindset, i.e. "I don't know what this is, I click it and I will eventually read information about it". So you don't go read the expounded text and come back, you just read normally, and you reach the text at some point.

Then it's a matter of whether it's easier to change the user or the library, but that's how I meant it originally.

[IanCal]

> I definitely know what you mean, but it's a problem with me being compulsive about having opened things stay open, not with the things themselves :P

I disagree, it's not about leaving things open. It's that I skip back and forth while reading and this moves a bunch of text. Suddenly, some things I was moving back and forth between have either gone or moved and it's not obvious which.

> I think that's the best argument so far. However, I think this is the "footnote" mindset (i.e. you go look up what the footnote is and come back). Expounder works under a more integrated mindset, i.e. "I don't know what this is, I click it and I will eventually read information about it". So you don't go read the expounded text and come back, you just read normally, and you reach the text at some point.

Fair enough that it's built for a different use. I find it very hard to have an animation happen near where I'm looking but entirely ignore it, so I'll look over to see what's happened.

[gravity13]

> By the time you've read the explanation, you've moved past it

Not with dense material. Often, I'll read through a chapter quickly, then go through the derivation of something three or four times until I understand it deeply, then re-read the chapter again once or twice to fully grasp it (at which point the derivation is just taking up space and I want to understand the grander scheme). Granted, I'm applying my approach to upper-division to grad-level physics textbooks, but that's the extreme I'm personally hoping to make more approachable for people.