At Agile 2009, Mary Poppendieck gave a talk on the theory behind craftsmanship. She starts out by giving some stats on Hockey Players from the book Outliers. 40% of elite Canadian hockey players were born between January and March, 30% April – June, 20% July – September, 10% October – December. The cut-off date is the end of the calendar year. So the ones born in December are at a disadvantage since they will be the youngest. The same applies for European football players.Mary then defines talent (nature) as abilities, powers, and gifts bestowed upon a person; natural endowments; general intelligence or mental power. Also, talent (nurture) is a special innate or developed aptitude for an activity. Talent is overrated. The most accomplished people need around ten years of deliberate practice before becoming world class (ten-year rule).
Next Mary defines deliberate practice: Identify a skill that needs improvement, devise a focused exercise designed to improve the skill, practice repeatedly, obtain immediate feedback and adjust accordingly, focus on pushing the limits expecting repeated failures, practice regularly and intensely up to 3 hours a day.
Then Mary elaborates on the four elements of deliberate practice:
1. Mentor: masters, teachers, deeply knowledgeable and involved. They hire and grow people, review and guide work, set technical standards, and ensure technical excellence.
2. Challenge: do it frequently and it will become easy, test/integrate/release early and often, change the code frequently, assign challenging work assignment, focus on constant improvement of the product, process, and people. Don’t get comfortable, get better.
3. Feedback: Immediate feedback: Design reviews with mentors providing guidance, common code ownership with peers providing visibility, TDD, CI, customer feedback at every iteration, escaped defect feedback and analysis. Focus on what’s not perfect so it can be improved. You have to ask constantly “why are we doing this?” Bad news first!
4. Dedication: skill development takes time in place, time to learn, and time to invent. Also need motivation, and career paths for technical experts.
Mary wraps up by stressing the importance of clean code and going over the Software Craftsmanship manifesto. We value not only working software but also well crafted software, not only responding to change, but also steadily adding value, not only individuals and interactions, but also a community of professionals, not only customer collaboration but also productive partnerships.This presentation is available on InfoQ at http://www.infoq.com/presentations/poppendieck-deliberate-practice-in-software-development
