Knowledge elements are the fundamental units of thought and discourse.
They help you:
Appreciate the elements of good discourse
Identify the essential characteristics of different genres and literary forms
Understand what you are reading (grasp the shape and flow of a text)
Determine the parts of discourse that deserve more attention
If you pay attention as you read books, listen to podcasts, and engage in conversations, you will find these elements over and over again.
Instead of merely highlighting things that catch our attention in a book or taking note of things that interest you from a lecture, you might find it useful to go one step further and identify the type of information you are capturing.
There are a couple of reasons for this:
First, it will tell what to do with that information. Provocative claims should be analyzed. Possible solutions should be tested. Interesting stories should be shared with a friend. "Highlights" is a very poor catchall for what you capture from your reading.
Second, it will help you know how to re-use that information. Once you capture these blocks of information, you have the raw materials to re-use them in your writing and conversation. And you can do this with more than just direct quotes.
Defining terms will be important here, because many of the terms for elements are used in multiple domains and subjects. But a syntopical exploration of each element will (I think) be useful. It will provide an interesting set of tools for reading and writing.
For each knowledge element, you will (eventually) find:
a definition
a short summary of the idea
an outline of topics that explore its relevance and use
real examples from authors, books, etc.
a toolkit with a collection of tips, tricks, mental models, patterns, heuristics, key concepts, templates, and leverage points
any cross-references to related elements
a list of references for further reading
You can also view a complete list of elements on the Element Index.