# The mechanism sketch for popular science reading

A science explanation can feel clear until you try to name what enters a system, what changes, and what leaves. This sketch tests understanding without copying the diagram.

## Sketch the mechanism

Save one page that makes the method useful, then complete the fields in your own words:

| Field | Prompt |
|---|---|
| **Input** | What material, signal, or condition begins the process? |
| **Process** | What sequence or interaction changes it? |
| **Output** | What observable result follows? |
| **Failure** | Under what condition would the result not occur? |

Keep the page number as the route back to the source. Avoid copying a protected passage when a short paraphrase will do.

## Find the weak link

- Mark the step you can describe least precisely.
- Separate correlation from a proposed causal step.
- Check whether the chapter presents the mechanism as established, modeled, or hypothetical.

Write one working sentence:

> My current reading is ____________________________________________.

## Review rule

After the section, redraw the four boxes from memory. Then reopen the book and correct only the missing link; do not treat recall as proof of accuracy.

## Boundaries

This is a private reading-reflection aid, not a quotation archive, plot substitute, academic citation, factual verification, or proof of an author's intention. For consequential claims, return to the full passage and verify outside facts independently.

## Optional iPhone workflow

I am the developer of **Reading Journal: TabMap**, an iPhone and iPad companion for physical-book readers. It lets a reader save a page, a reason such as **Question** or **Keep**, and an intensity, with an optional private note. The free version includes one complete book map; no account is required, and books, markers, labels, and optional notes stay on the device.

[View Reading Journal: TabMap on the App Store](https://apps.apple.com/us/app/reading-journal-tabmap/id6796663483)

Campaign marker: `day12-strong-distribution`