Proving the benefit of consistency in tech comm

To ensure efficiency and accessibility of technical communications, use consistent, common formatting, for example, for interface elements. What sounds obvious to many technical communicators is actually proven in academic studies. This post is for people looking for proof that consistency has a benefit in technical communications.

I’m taking my cue from a question that appeared in a LinkedIn group:

[I need to] find studies or tests that show that it is value-adding to have consistent formatting on e.g. User Interaction elements (such as buttons or handles) in your instructive documents. Can anyone share studies or tests in this area?

I can offer an answer on two levels:

• The general benefits in terms of human perception
• The particular benefits of consistent documentation

The neuroscience of consistency

Human perception favors consistency. The mind groups things easier, faster and with more confidence, if they’re consistent and have something in common.

Gestalt law of similarity: The mind groups similar elements into collective entities, from Wikipedia.

Psychological studies have shown two principles by which human perception groups things: Proximity and similarity. For a comparison of these two principles and further references, see Han, S., Song, Y., et al. (2001). Neural substrates for visual perceptual grouping in humans. Psychophysiology, 38, 926-935. Han and colleagues actually quote several studies that “proximity is a more salient cue than similarity.”

In technical comunications texts, we usually can’t practically lump all names of windows or fields across all topics together to show they’re related.

But we can resort to similarity to help readers understand that we mean a GUI element at each occurrence. If we always write their names in bold, for example, readers will recognize that similarity across topics and learn to scan for it (whether they’re aware of it or not). If we always mark up GUI elements somehow, sometimes in bold, sometimes in italics, readers are more likely to wonder if the different markup has a meaning – and they won’t be able to scan the text as quickly and reliably.

For more psychological research and how it applies to technical communications, refer to Chris Atherton‘s excellent and accessible article “What and where?” in ISTC’s Communicator quarterly, Spring 2011, pp. 28-29.

Studies of applied consistency

So much for the theory. But does consistency, for example in formatting GUI elements, have an actual benefit in documentation?

One very good resource to argue for such consistency is the Research-Based Web Design & Usability Guidelines. This 292-page tome sets out “to provide quantified, peer-reviewed Web site design guidelines”. It was published by the US Department of Health and Human Services in 2006 and is available for free download, as a book and as individual chapters.

Chapter 11 on “Text Appearance” has a couple of applicable guidelines:

#2 Format common items consistently

Common, recurring items, such as telephone numbers, time records, button and window names should be formatted consistently, according to expert recommendations in: Ahlstrom, V. & Longo, K. (2001). Human factors design guide update (Report number DOT/FAA/CT-96/01): A revision to chapter 8 – computer human interface guidelines.

#4 Ensure visual consistency

Visual consistency, including the appearance of characters in interfaces, reduces user errors. “Studies found that tasks performed on more consistent interfaces resulted in (1) a reduction in task completion times; (2) a reduction in errors; (3) an increase in user satisfaction; and (4) a reduction in learning time.” The quoted studies include:

• Adamson, P.J. & Wallace, F.L. (1997). A comparison between consistent and inconsistent graphical user interfaces. Jacksonville: University of Northern Florida, Department of Computer and Information Sciences.
• Eberts, R.E. (1997). Cognitive modeling. In: G. Salvendy (ed.), Handbook of Human Factors and Ergonomics, 2nd ed., New York: John Wiley & Sons.
• Ozok, A.A. & Salvendy, G. (2000). Measuring consistency of web page design and its effects on performance and satisfaction. Ergonomics, 43(4), 443-460.
• Schneider, W., Dumais, S.T. & Shiffrin, R.M. (1984). Automatic and control processing and attention. Varieties of Attention. New York: Academic Press, 1-27.
• Schneider, W. & Shiffrin, R.M. (1977). Controlled and automatic human information processing: detection, search and attention, Psychological Review, 84, 1-66.

Specifically, Ozok and Salvendy in 2000 confirmed the earlier studies that visually inconsistent interfaces lead users to poorer performance and more errors, see the summary in the Human Factors International newsletter.

– I hope this little field trip into academia can help you to prove that consistency not merely seems somehow desirable and logical, but has actually cognitive benefits proven in studies.

Advertisement