Taking ownership

A lot of books/articles say about taking ownership.

The boy-scout rule says about leaving the place cleaner than it used to be.

But what is the scope of ownership? If I am changing a method in a class, am I responsible for all the class? How cam we make it measurable?

In my opinion, you are responsible for all the code which is being touched by request, you’re working on.

The reason here is: you’re making change mostly to influence request/responce. So, anyway, you have to understand what you’re doing, so you have to investigate the whole data flow from request till response.
Since you’re doing it — it’s a good time to apply the Boy scout rule.

Also, you’ll spot all the downstream thins which are influenced by your code.

Now, if you take a step back, you’ll understand, that less coupling you have — less ownership and responsibility you’re taking by changing one thing. That’s why we like classes as small as possible.

Also, it makes it easier to refactor.