I got a Critical Rationalism (CR, aka Popperian Epistemology) question today about how conjecturing/brainstorming/guessing works. I'd already given an initial answer that people already know how to brainstorm, so what's the problem? But there was further concern about a missing piece in CR.
I've seen questions like this before. They involve a misunderstanding of epistemology. People are looking for theory of epistemology to be a standalone complete framework, rather than a collection of useful knowledge.
CR takes human knowledge and adds and subtracts some things. It does not replace all existing knowledge from the ground up.
This is really important. I've seen a lot of questions about CR and *stuff people already know how to do*. And questions about CR not being totally complete instructions for every detail of how to do things.
It's not supposed to replace your life. It's supposed to augment your life.
CR doesn't teach you how to type. You already know how to type. But not perfectly. No one here is a perfect typist. And I'll bet some people here actually make frequent typing errors, press some keys with the wrong fingers, need to look at their keyboard sometimes while typing, etc
Nevertheless, CR leaves your typing skill alone. It doesn't offer a new and better way to type. Your typing may be imperfect, but CR isn't trying to help with it and make it better. (At least not in any direct way. Indirectly CR helps with everything.)
You already know English. Your grasp of English has various flaws. Nevertheless, CR largely leaves it alone. CR does not try to replace your knowledge of English with a better understanding.
CR builds on top of pre-existing flawed knowledge you have – like typing and English.
In the case of English, CR does give a few tips, changes, and improvements. E.g. CR offers some clarifications on the meanings of "science", "justified true belief", "positivism", "induction", "authority", "rational" and "knowledge".
With brainstorming or other guessing/conjecturing, it's a pre-existing skill you already had before you'd ever heard of CR. Like English and typing. (For most people).
CR does offer some tips, changes, and improvements for how to brainstorm. But CR does not offer a from-the-ground-up replacement. Why would it? Your ability to brainstorm ideas, while imperfect, does basically work. Yes people get stuck in some ways (and a lot of the tips, both from CR and other places are directed at that). But the big picture is you can think and don't need that to be replaced anymore than you need a replacement for your knowledge of English.
Take what you already have and improve it and solve problems with it. But just look for reforms, not a fully-formed complete replacement.