I'm using Java 6.

Sometimes I find myself doing something like this.

```
Map<String,List<Integer>> myMap;

```

This is just an example. It can go deeper than that.

What are the pros and cons of creating a new interface and doing this instead?

```
Map<String,NewInterface> myMap;

```

The only thing I see is it's a little more readable. Anything else in terms of performance, modularity, coupling, or *you name it*?