This will be part presentation and part discussion about general principles that are apart of good Object Oriented Design.    Some topics that will be discussed include:   

• Single Responsibility / Separatrion of Concerns 
• Open / Closed Principle
• Dependency Inversion Principle 
• Law of Demeter 
• Interface Segregation Principle
• Liskoff Substitution Principle    

This will be as much a discussion as a presentation.  Come prepared to be engaged in a spirited dialog.