What does it mean that progressive summarization?

Highlight the key points then summarize the highlights — each pass concentrates the value.

Example: You save an article on organizational decision-making to your notes app. On the first read, you bold the sentences that strike you as most important — maybe eight out of sixty. Three weeks later, you are preparing a presentation on how your team makes decisions. You reopen the note and scan the bolded passages. Two of the eight are directly relevant. You highlight those two in a different color. You also write a three-sentence executive summary at the top: 'Organizational decision speed depends on two variables: the reversibility of the decision and the cost of delay. Reversible decisions should be made by the nearest person to the information. Irreversible decisions justify committee deliberation.' That summary did not exist in the original article — it is your compression of the pieces that matter for your specific purpose. A month later, when a colleague asks you how to think about decision authority, you open the note, read the three-sentence summary in five seconds, and give a clear, precise answer. You have distilled a 3,000-word article into three sentences across three separate encounters — and each encounter took less time because the previous pass had already done part of the work.

Try this: Choose five notes from your existing collection — articles you saved, book highlights, meeting notes, anything. For each one, apply the first two layers of progressive summarization. Layer 1: Read through and bold the passages that contain the core ideas — aim for no more than 10 to 20 percent of the total text. Layer 2: From the bolded passages, highlight the ones that are most surprising, most useful, or most likely to be relevant to your current projects — aim for no more than 10 to 20 percent of the bolded text. Do not write an executive summary yet (Layer 3). That layer should only be added the next time you revisit one of these notes for a specific purpose. After completing Layers 1 and 2 on all five notes, open each note and time how long it takes you to grasp the core idea by reading only the highlighted passages. Compare that to how long it would take to re-read the full note. The ratio between those two times is the compression dividend — the time you will save on every future retrieval.