Robert Cecil Martin, commonly called Uncle Bob, is a software engineer, advocate of Agile development methods, and President of Object Mentor Inc. Martin and his team of software consultants use Object-Oriented Design, Patterns, UML, Agile Methodologies, and eXtreme Programming with worldwide clients.
He was Editor in Chief of the C++ Report from 1996 to 1999. He is a featured speaker at international conferences and trade shows.
An extremely basic overview that does not go nearly far enough into the question of determining the practical granularity of the concept of responsibility in context. Perhaps it was more useful within the book from which it was excerpted.