My daughter use to eat pizza one ingredient at a time. She would patiently sit and take her slice apart, making separate piles of pepperoni, green peppers, olives, cheese, and crust. She would then eat each ingredient in turn. I am reminded of the bizarre (and short-lived) practice when I see how many people do topic type design (or at least, how they talk about it).
Designing topic types, I read in many articles and presentations, is about dividing information up into different types. The number of types proposed varies, but the principle always seems to be the same: there are distinct types of information, and the goal of topic design is to pick them out of your content and make separate neat piles of them.
My daughter pretty soon got sick of eating pizza one ingredient at a time, and I’m pretty sure most readers have no appetite for consuming information one type at a time either. What the reader wants is all the information, of whatever kind, that satisfies their present hunger. What they want is a 10 inch thin-crust lunch pizza that they can eat quickly and that won’t weigh them down and cause then to fall asleep around 2PM.
Why not a slice rather than a personal pizza? (That would be a chapter in a book, if anyone is getting lost in the metaphor.) Part of the problem is that most pizza places don’t offer their gourmet pizzas by the slice. You are kind of stuck with two or three generic choices.
Actually, that’s not such a great metaphor for a traditional technical manual. A better metaphor would be a super el-supremo grande pizza with every single available ingredient on it. Every slice has anchovies, whether you want them or not, and you end up trying to pick out the ingredients you don’t like and leaving them on the side of your plate.
And that is where we came in. Picking apart content and separating it into piles.
This is not what topic type design should be about. Topic type design should be about assembling all the content that satisfies the reader’s reason for reading, either in the topic itself, or by active and immediate references. Topic types for different types of tasks will be precise and distinct, just as the recipe for different gourmet pizzas are precise and distinct. They will be collections of information of different types that work together to serve a particular end for the reader.
Topic type design, therefore, should not be about separating information into different types, but about combining different types of information in particular ways to meet the specific information needs of the reader.