This month, we're going to explore Test-Driven Development (TDD) - the practice of writing a test before writing code that implements the tested behavior. David Vydra (standing in for his associate Rob Meyers stuck out of town) explains the two basic types of TDD: the original unit-level approach used mostly by developers, and the Agile-inspired Acceptance-Test Driven Development (ATDD) which involves the entire team.

The various difficulties in adopting TDD include: developers who don’t spend a few extra moments to look for and clean up a new bit of code duplication; inexperienced coaches who confuse the developer-style TDD with the team ATDD; and waffling over the use of TDD, which limits its effectiveness. Done well, these practices help the Scrum/Agile team succeed, but resistance (overt or subtle) to these practices is deeply rooted in our brains and our cultures. 

David Vydra has been building commercial software for over 20years. His current focus is Agile Testing coaching and test toolsdevelopment. He blogs at http://testdriven.com

Rob Myers is founder of Agile Institute (www.agileInstitute.com) and a founding member of the Agile Cooperative (www.AgileCooperative.com). He has 25 years of professional experience on software development teams, and has consulted for leading companies in aerospace, government, medical, software, and financial sectors. He has been training and coaching organizations in Scrum and Extreme Programming (XP) management and development practices since 1999.  Courses include Essential Test-Driven Development and Essential Agile Principles and Practices. Every course is a blend of enjoyable, interactive, hands-on labs; plus practical dialog towards preserving sanity in the workplace. Rob also performs short- and long-term coaching to encourage, solidify, and improve the teams Agile practices.