This is the hardest part of writing for me, especially blog posts.
I can never decide if I'm writing for a) highly technical readers who know 95% of the concepts my idea is based on, and I just want to connect the concepts together in a way the they might not have thought of, b) generally technical readers who have a grasp of the concepts my idea is based on, but will need some details to tie them into the idea I'm building on top, or c) readers who are not-especially-technical in the field, who might be nevertheless be interested in how a few things works, and my idea too.
I feel like part of it is that I am all these readers, depending on the subject. I enjoy reading articles about the areas of software dev I'm deeply interested in, but also about the odd idiosyncrasies of software that is used in fields I don't normally cover, but I also enjoy reading articles about e.g. the challenges involved in developing geothermal drilling systems, or elevator systems in 80+ story buildings, despite having very little experience in either.
I keep going through cycles of "If I just explain this part in a bit more detail, the post will be accessible to an order of magnitude more readers" to "this is way too long, I should cut some explanations, or add footnotes, or more wikipedia links" to "I'm assuming way too much previous knowledge here, or asking the reader to do too much extra work to follow my point".
Good question, and one I'd like to see discussed more too. From my point of you, your point "a)" is the one I never choose. In my opinion, one could rarely write something for that audience which might be novel to them. Perhaps I'm just not that smart, but to me, when I picture the true masters in my field, I rarely need to communicate anything to them that they haven't figured out for themselves already, and in the rare case that I might, those types of people don't mind a bit of revisiting of the fundamentals anyway.
My favourite type of writing is one that also comes in handy to myself a couple of years down the line, which inevitably involves a modicum of handholding and starting from some fundamentals. So I'd say most of the articles should be b) or c).
Yeah, I find picking the audience difficult too. For my blog posts, I want to include the details for specialized readers, but also make the post accessible to the generally technical readers (roughly the HN crowd). (If I wanted to write for only the first group, I'd write academic papers.)
My solutions are to add enough background for someone who isn't an expert (even if it seems repetitive), and to use extensive footnotes for information that most people won't care about. Also, I try to put topics into a broader framework: a few paragraphs on history and why the topic is important. A narrative framework helps too, so even if someone doesn't follow all the details, they get a sense of going on a path e.g. from problem to solution. I also try to break up massive chunks of text with photos or diagrams but worry that I lean on this too heavily.
When I read popular books on scientific topics, I try to study the techniques that they use. For example, "An immense world" is crammed full of interesting facts and stories, keeping the book even though it is discussing technical concepts of sensory perception. "Immune" describes the immune system in detail, making heavy use of metaphors and imagery and repeating these throughout the book. Other books focus on the people, moving the technical details into the background.
I'm no expert on this, of course. People seem to like my blog posts, though, so I figured I'd share my thoughts.
This is the hardest part of writing for me, especially blog posts.
I can never decide if I'm writing for a) highly technical readers who know 95% of the concepts my idea is based on, and I just want to connect the concepts together in a way the they might not have thought of, b) generally technical readers who have a grasp of the concepts my idea is based on, but will need some details to tie them into the idea I'm building on top, or c) readers who are not-especially-technical in the field, who might be nevertheless be interested in how a few things works, and my idea too.
I feel like part of it is that I am all these readers, depending on the subject. I enjoy reading articles about the areas of software dev I'm deeply interested in, but also about the odd idiosyncrasies of software that is used in fields I don't normally cover, but I also enjoy reading articles about e.g. the challenges involved in developing geothermal drilling systems, or elevator systems in 80+ story buildings, despite having very little experience in either.
I keep going through cycles of "If I just explain this part in a bit more detail, the post will be accessible to an order of magnitude more readers" to "this is way too long, I should cut some explanations, or add footnotes, or more wikipedia links" to "I'm assuming way too much previous knowledge here, or asking the reader to do too much extra work to follow my point".