Joshua Kerievsky has been programming professionally since 1987. He founded Industrial Logic, a company specializing in patterns, Extreme Programming (XP), and other techniques for more successful software development. He began his career as a professional programmer on Wall Street, where he developed numerous financial systems for credit, market and global risk departments. Kerievsky is an active member of the patterns and XP communities, and the author of many articles, simulations, and games.

Joshua recently published a book called RefactoringToPatterns.

In 1989 Kent Beck and Ward Cunningham introduced CRC (Class- Responsibility-Collaborator) cards to the OOPSLA crowd as a tool for teaching object-oriented thinking. In that classic paper, they also hinted at the power of using CRC cards as a technique for gently, gradually introducing complex designs. This talk re-introduces several informal techniques that can be helpful in deciphering patterns as well illustrating new patterns. And just for balance, we'll briefly look at how UML (Unified Modeling Language) can be simply used to express design subtlies. There's a time and place for both informal and more formal views.

Rebecca Wirfs-Brock is an internationally recognized leader in the development of object design methodologies and is a consultant to enterprises of complex object architectures and designs. She invented the set of development practices known as Responsibility-Driven Design. Among her widely used innovations are use case conversations and object role stereotypes. Via her courses and conference tutorials she has taught object design concepts to thousands of programmers.

She is the regular design columnist for IEEE Software and the author of the classic text, Designing Object-Oriented Software. Her most recent book, Object Design: Roles, Responsibilities and Collaborations, was published in 2002. She also blogs regularly.