For nth, and I'm sure not last time, I'm sliding into a conversation about defining practices, labeling some of them as "best", and probably the C-word (certification). It's a familiar discussion, and although we've barely started it, I can predict much of where it will go. It's driven by a perfectly reasonable desire to identify who are the better software developers, and how existing developers can improve their abilities.
When people get into these conversations, they usually end up in trouble. Either the group gets into heated discussions and cracks up, or the group doesn't have heated discussions and produces something that others deride. The heart of why this happens, and why I don't see any single, widely-recognized certification program for software development coming soon is that there is no single, well-agreed way to develop software effectively.
Instead what we see is a situation where there are several schools of software development, each with its own definitions and statements of good practice. As a profession we need to recognize that multiple schools exist, and their approach to software development development is quite different. Different to the point that what one school considers to exemplary is considered by other schools to be incompetent. Furthermore, we don't know which schools are right (in part because we CannotMeasureProductivity) although each school thinks of itself as right, with varying degrees of tolerance for the others.
I'm using "school" here in the style of this definition:
4 a: a group of persons who hold a common doctrine or follow the same teacher (as in philosophy, theology, or medicine) <the Aristotelian school>; also : the doctrine or practice of such a group b: a group of artists under a common influence c: a group of persons of similar opinions or behavior; also : the shared opinions or behavior of such a group <other schools of thought>
I came across this notion explicitly from the Context-Driven School of Software Testing (see James Bach and Brett Pettichord). I like their way of looking at this because it's a model that explains why intelligent software developers have such different approaches.
The Context-Driven folks have done some looking at different schools within the testing world, but I don't know of any good attempt to classify the schools within the broader world of software development. I feel a sense of belonging to a school, one that for me is rooted in the people I met through OOPSLA in the 90's. Object-orientation is a key practice of this school, as is agile methods. You could reasonably argue that this is the agile school, except I think that agile methods are a core component of this school's thinking but not the whole picture. The leaders of this school include people like Ward Cunningham, Ralph Johnson, Kent Beck, and Robert Martin. ThoughtWorks is, on the whole, an organization that follows this school (which is why I'm comfortable here).
But despite this sense of a somewhat coherent school, there's still many open questions. Is it best to think of the agile world as one school or many (are Scrum and XP different schools or part of the same)? What are the major schools out there? What exactly defines a school of thought?
I don't have much of an answer to these questions, but the key point to remember is that there are multiple schools of thought about how to develop software effectively. We may not think much of the other schools to our particular one, but we are foolish not to recognize that other schools exist.