I'm interested in using metaphors and methods from programming and engineering to make documentation better. There are some obvious elements that are ripe for stealing in terms of process (scrum, iteration, etc.) as well as tooling (issue tracking, version control.) As I've continued to explore the connections and metaphors have become less obvious, but remain very helpful.
Recently I've been thinking about and using the idea of inheritance to help address content duplication issues. The new approach to tutorial content is one of these applications. Actually, this is a bit of retroactive intellectualizing: the need for reuse came first, and relating this back to inheritance is an idea that I want to explore.
I'm thinking about inheritance in the same way that we talk about the inheritance of classes in object oriented programs.
In the past, I've talked about the failure of the promise of single sourcing to solve the complexity problems in documentation as being related to the failure of object oriented programming styles to resolve code duplication and promote widespread code reuse. Or, if not related, symptoms of related causes.
For code, I think the issue is that while there are a couple of applications for inheritance (i.e. representing trees, some basic templating,) it's not a universally applicable metaphor. The mantra composition over inheritance draws attention to the fact that "has a" relationships are more prevalent and useful than "is a" relationships.
Tactically, speaking, using inheritance rather than simple inlining or inclusion is quite helpful for thinking about content reuse in documentation. Inlining is technically easy to implement, but doesn't actually help facilitate content reuse because it's hard to write content for inclusion that's sufficiently "context free," whereas using inheritance makes it possible to reuse structures and portions of content without requiring writers to write context-free content.
Inheritance isn't perfect of course: if you have to overload all or most inherited elements you end up with a confusing mush that's hard to untangle, but it's a decent starting point.
Onward and upward!