Progressive Summarization is a note-taking technique that focuses on extracting, summarizing and distilling information to the core ideas.
You can achieve this by re-reading the text and the most important pieces several times, each time narrowing down to only the paragraphs or sentences that contain the key messages. For each note, you have several layers:
Moving from one layer to another is done at different interval of times and not all the steps at once. For example, level 2 can be done in the same day or the next one from the time of reading the content. Level 3 pass can be done after one week and level 4, several days later.
When revisiting a processed note, it is way faster and easier to recall the content of the note compared with re-reading the original content. Since the information is summarized to the key ideas, if more details are needed, you just need to follow the sequence in reverse, from the executive summary to the captured highlights.