# Sillito's stages of program understanding

> Jonathan Sillito가 제안한 프로그램 이해의 단계

<Jonathan Sillito>가 제안한 프로그램 이해의 단계

> According to Sillito, who observed 25 programmers while they were reading code, programmers typically start by searching for a **focal point** in the code. This can be the entry point in the code, such as a `main()` method in a [Java](https://wiki.g15e.com/pages/Java.txt) program or an `onLoad()` method in a <web application>. It may also be a line that is interesting for another reason, like a line at which an error has just occurred or a line a profiler has flagged as consuming many resources.
>
> From this focal point, programmers can build their knowledge….
>
> 1. Find a focal point.
> 2. Expand knowledge from the focal point.
> 3. Understand a concept from a set of related entities.
> 4. Understand concepts across multiple entities.
> 
> … Some frameworks and techniques, like <Dependency injection> frameworks, can fragment focal points so that they are far apart and hard to link together. To be able to know where to start, you need to understand how the framework links code together. --Chapter 5, [Programmer's brain](https://wiki.g15e.com/pages/Programmers%20brain.txt)