Volume 1, Number 2
May 1, 2006


When Legibility, Readability & Usability Intersect, Then We Reach Our Target Audience

by Suzanne Webb

Unless we move legibility, readability, and usability to the forefront of our design practices, we will unquestionably lose our audience.

target: the intersection of legibility and readability

If we want to reach our target audiences when presenting text-based information, we as content specialists (designers, programmers, writers, and project managers) need to constantly consider usability. "Usability is often measured by studying the design of the table of contents, index, headings and page layout as well as determining the appropriate technical level" (5) according to Laura Gurak; moreover, "for maximum usability we must write from the user's point of view" (42). To accomplish this, we must move these crucial concepts of legibility, readability, and usability to the forefront of our design practices else we will unquestionably lose our audience. Too often we seem to overshadow them with other "more serious" concerns when these are the serious concerns in terms of satisfying our users..

Strong Contrasts Grant Legibility

Legibility refers to how easy it is to recognize bursts of copy. Headlines, callouts, signs, buttons and the like all affect the legibility of a product. Robin Williams, author of The Non-Designer's Web Book, offers help to ensure legibility; use a strong contrast between the type and the background color. She suggests we use the standard of black-on-white for the highest contrast (214). A reverse type (white-on-black) while striking, may alienate older readers as their eyes are not as geared for lengthy reading in dimmer conditions as Kevin Connolly's research indicates. "A sixty-year-old retina only receives one-third as much light as its twenty-year-old counterpart" (Connolly Thesis). Connolly confers with Williams; "legibility is enhanced by high luminance and color contrast, larger targets, [and] increased...spacing" (Thesis).

Perceived Legibility and Font Choice

Looking past how legibility relates to contrast, psychology students in the Software Usability Research Lab (SURL) at Wichita State University conducted studies on the legibility of different typefaces; these studies did not produce scientific results, but participants perceived Courier, Verdana, Georgia, and Times as most legible. If perceived legibility works for the end-user, then it is our duty as the designer to adhere to their perceptions.

Can Users Read Page After Page of the Text?

The separation of legibility and readability is oft misunderstood. Williams says readability is how "easy it is to read a lot of text, extended text, pages and pages of text" (214). Connolly confers saying readability is also measured by reading rate and comprehension (Thesis). While many decisions directly affect the readability of a project, both type font choice and line length are at the forefront. Making a font choice is a complex issue. Serif? San Serif? Bold? Regular? 10-point? 14-point? More than likely, according to Robin Williams, in a long passage of text a serif typeface will be easier to read. The serifs help to guide the eyes along the line. Furthermore, the optimal type size is between ten- and fourteen-point for on-screen reading (214). And, while more users are attempting to read our texts on-screen, we must also address those who wish to print our information.

What is Suitable Word Choice?

Specific word choice too, affects readability. Agricultural Communications reports that the Rudolf Flesh formula should govern all typesetting decisions. This formula combines reading ease (readability) with human interest (usability). There are four main points: 1) The more syllables, the harder to read and understand; 2) The more words, the harder to read and understand; 3) The more words about people, the more interesting, and; 4) the more sentences addressed to an audience, the more interesting (Readability). Agricultural Communications' suggestions demonstrate that even when we present technical information to an audience, traditional Anglo-Saxon words instead of Latinate as well as concise wording will help to incorporate our end user into the work and give them a more enjoyable experience. This improves the readability and therefore the usability of our information.

What is Optimal Line Length?

A substantial share of readability is attained by employing an optimal line length. Some controversy exists. Williams states that shorter line lengths are better because the eyes can't follow as well across the whole screen (214). Susan Wheeler, author of The Visual Design Primer finds that "lines ... too short or too long disrupt the reader's rhythm" (46). Wheeler believes these disruptions are 100% preventable. "A long line causes doubling (rereading the same line) because the reader has trouble finding the start of the next line. A shorter line constantly sends the reader back to the left edge after only a few words, so a comfortable rhythm is never established" (46). Humanfactors.com compiled data from several studies and reported "users preferred" a four-inch line length. While users read faster at a longer line length, the "users tend to prefer four to five-inch-wide lines" (UI Design). Discovering what the users prefer is the important finding-the finding we developers must adhere to. It's not about the reading speed; it's about usability and that translates to user preference.

Positive User Opinion is the True Measure

In Web Design Concepts and Best Practices, Carolee Cameron defines usability as "the degree to which a web site is efficient and easy to use. Ease of use, efficiency of the design, visual consistency and a clear focus on meeting the needs of users are hallmarks of usability. A usable website should also be memorable, result in few errors, and provide a level of satisfaction for the user" (160). Cameron also stresses that usability "is as important to the site's owners as it is to its users. Web sites need to be efficient and easy to use or they will lose visitors, which could result in the loss of revenue. Visitors who experience the smallest degree of confusion or frustration while on a site will leave" (160). One of the ways to we developers and writers can ensure these things do not happen is to utilize focus groups and beta testing. Cameron believes that rules of thumb should include: "90% of users should be able to find the information they need in less than one minute. 90% of users should say they like the site and will return" (164). There is no substitute for the end-users' opinions and their interpretation of a product's performance.

Who Is Our Target Audience?

We designers must continue to ask, "Who is our target audience" and channel a majority of our efforts into reaching and pleasing that audience. We will reach them through our planning for who they are and only then through our design or our words. "The more precisely defined [our] target audience is the more efficiently and effectively [we] can present the information" (Williams 81). And, while each of these interrelated concepts - legibility, readability, and usability - is much of much broader scope than can be addressed in this particular paper, let's face it, only when our information is efficient and effective - is it then usable. By gaining a deeper understanding of these graphic design considerations along with constantly considering usability, we can enhance our audience's experience and keep them consuming our works.

To Ensure the End-User's Best Experience, Answer These 5 Questions:

1) How can I create contrast?

2) What font should I choose? Verdana? Times? Arial?

3) Can I use about a 5-inch line length?

4) Should I re-word anything? Is it difficult to understand? I know it, but will they understand it?

5) Employ a focus group or perform beta testing on a sampling of your future audience.

About the Author

Suzanne Webb

Suzanne Webb , MA student in Digital Rhetoric and Professional Writing has earned an AS in Computer Science, and BAs in Creative Writing and Psych, blending creative and technical writing, multimedia and graphic design, advertising and psychology for a unique twist on her title "Content Specialist." New to Michigan State in 2006, she teaches WRA150: "Consider Literacy." Future plans include teaching, researching, attending Spartan sporting events, and earning a PhD.

Email: webbsuza AT msu DOT edu

Web: http://www.msu.edu/~webbsuza/atw


"Readability" Agricultural Communications. Texas A&M
<view source>

Cameron, Carolee
Web Design Concepts and Best Practices. 2004.

Connolly, Kevin
"The Aging Visual System," University of Calgary <view source>

Gurak, Laura and John Lannon
A Concise Guide to Technical Communication. 2nd Ed. 2004.

Human Factors International "Optimal Line Length, UI Design Newsletter. November, 2002.

"Line Length,"
Web Style Guide
<view source>

Wheeler, Susan and Gary
The Visual Design Primer. 2002.

Williams, Robin
The Non-Designer's Web Book. 1998.

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