Structural Patterns and the Hierarchy

Structural patterns are the solutions information architects use to define a coherent, navigable structure for a digital information space's pages. The hierarchy, or taxonomy, is the most common structural pattern: a top-down structure with the home page at the top, comprising content organized into categories that have parent-child relationships, progressing from general to specific.

A strict hierarchy keeps categories mutually exclusive, with each page belonging to just one category. A polyhierarchy allows a page to belong to more than one category, which is often necessary for large spaces but should be used sparingly to avoid confusing users' mental model of the structure. Designing a hierarchy means balancing its breadth, the number of items at each level, against its depth, the number of levels overall. As a general guideline, keep the number of categories at any one level below fifty; if a category has too many items, divide it, and if there are too many categories, combine similar ones.

A hierarchy that's too broad overwhelms with choices; one that's too deep buries content beneath too many clicks. Neither failure looks the same, but both send users away empty-handed.

Exercise

The scenario: A software documentation site's hierarchy has three top-level categories: "Getting Started," "Reference," and "Troubleshooting."

Under "Reference," there are 68 subcategories listed alphabetically with no further grouping, one per API endpoint. Under "Troubleshooting," there are only 2 subcategories, each containing over 40 individual articles with no further breakdown.

Analytics show a high bounce rate on the "Reference" landing page, and long session times with many back-clicks on "Troubleshooting" articles.

1. What's the primary structural problem with the "Reference" section?
2. What's the primary structural problem with the "Troubleshooting" section?