Resource Shelf noted a study today about the effects of Web document formatting on user comprehension and behavior (PDF). The University of Washington researchers recreated several different versions of an information site, with one set lacking global navigation (Figure 1 below) and another having tabbed navigation (Figure 2). Other variations included no introductory text (1A, 2A), introductory text followed by bulleted categories (1B, 2B) and introductory text with embedded links (1C, 2C).

Figure 1: Three variations of pages without global navigation.

Figure 2: Three variations of pages containing tabbed navigation.

Some of the findings of how presentation influences reader behavior surprised the researchers:

• Introductory text (B) without embedded links doesn’t increase factual comprehension; nor does it increase total time spent on site
• Tabbed navigation (figure 2) doesn’t influence comprehension of the material, but it does encourage site exploration and increases user satisfaction.
• Introductory text with embedded links (C) increases referential comprehension (understanding how the material relates to other topics), but at the cost of severely reducing satisfaction-particularly in the absence of tabbed navigation (1C vs 2C)
• Link lists without introductions (1A, 2A) generate more page views than link lists with introductions (1B, 2B).
• Tabbed navigation (figure 2) increases the number of pages viewed. While not mentioned in the study, there’s likely an upper limit to how many navigational tabs you can add before this works against you. Just ask Amazon.

So, users like tabs (no surprise), but that introductory text isn’t necessarily going to help comprehension (surprise). Embedded anchor text is good for SEO and reader comprehension, but bad for reader satisfaction. As the abstract states, “structural cues that promote understanding are not necessarily those that promote exploration or enjoyment.” Choose wisely.

Kathryn A. Mobrand, Elisabeth Cuddihy, Edward Galore and Jan H. Spyridakis from the University of Washington published The Effect of Structural Cues on User Comprehension, Navigational Behavior, and Perceptions. Their study involved 282 engineering undergrads from UWA who reviewed Web sites based on the U.S. National Park Service Web site for Big Bend National Park in Texas.