9 - Note Size - A common question people have regarding the zettelkasten and note taking in general is one of note length. A good way to think of this is through the concept usability of information. We structure information such that it can be used repeatedly. You can think of notes in the same way.
a - smallest unit of usability is the letter. As you see I repeatedly make use of the letter a in this sentence.
word- is the next largest unit
phrase - can be used in multiple contexts
sentence - can be used in multiple contexts but is a bit awkward because it isn’t as usable as a word or phrase but not as robust as a paragraph. A good example of a reusable sentence is a quote. See 2A
paragraph- is often seen as the smallest unit of thought as it is usually what is necessary to get an idea across, with sentences being the parts that support or explain the paragraph (Shore 2016, pg 28).
section - can be thought of as multiple paragraphs.
Because one of the key ideas behind a zettelkasten is to remix ideas such that a note can contribute to multiple sequences of thought, an ideal note length is between a paragraph and a section. If you find yourself wanting to reference a sentence then it is fine to spin it off into its own note. But it’d be a waste of time to do so before that becomes necessary.