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A Practical Guide to Information Architecture ~ How people think about categories
More than one level – subcategories In all my descriptions above, I’ve talked about categories as if they are a single level. But they’re not. Categories contain sub-categories and sub-categories contain sub-categories and categories can be grouped into broader categories until they make a whole hierarchy of categories. We’ll talk about hierarchies and their different types briefly below, then in much more detail in chapter 16 (IA patterns).
Basic level categories If I asked what you were sitting on right now, I expect you would more likely say chair than furniture or office chair. If you were researching how to make your house more energy efficient you may tell me you were interested in finding out about saving water rather than sustainability or under-floor rainwater tanks. These examples represent an important concept in language and category theory – where we think and talk. I mentioned above that all categories can be broken down into subcategories and aggregated into broader categories. Even though this does happen, we tend to think and talk at a particular place in the category hierarchy. In categorisation literature this is known as the basic level category.
Furniture
Table
Kitchen chair
Chair
Office chair
Figure 10 – 2. A simple hierarchy for furniture
Bed
Recliner
Bookcase
Sofa
Desk
Electric chair