I like Eric Meijer's take on this. He said that the important property of interface are not the actual method signatures, but rather laws that the methods follo

I like Eric Meijer's take on this. He said that the important property of interface are not the actual method signatures, but rather laws that the methods follow when being called. I think it follows that with bigger interface, there are more laws to follow (for example, read() must be called after open() but not after close()), and as a consequence, utility of that abstraction gets more limited.