From http://guidelines.usability.gov and a few other sources…
“Vigorous writing is concise. A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts.”
-William Strunk Jr., in Elements of Style
- Make First Sentences Descriptive
- Limit the Number of Words and Sentences
- Use Active Voice
- Avoid Jargon
- Use Familiar Words
- Use Mixed Case with Prose
- Make Action Sequences Clear
- Define Acronyms and Abbreviations
- Use Abbreviations Sparingly
- Write Instructions in the Affirmative
- Limit Prose Text on Navigation Pages
Content is the most important part of a Web site
If the content does not provide the information needed by users, the Web site will provide little value no matter how easy it is to use the site.
When preparing prose content for a Web site, use familiar words and avoid the use of jargon. If acronyms and abbreviations must be used, ensure that they are clearly understood by typical users and defined on the page.
Minimize the number of words in a sentence and sentences in a paragraph. Make the first sentence (the topic sentence) of each paragraph descriptive of the remainder of the paragraph. Clearly state the temporal sequence of instructions. Also, use upper- and lowercase letters appropriately, write in an affirmative, active voice, and limit prose text on navigation pages.Make First Sentences Descriptive
Include the primary theme of a paragraph, and the scope of what it covers, in the first sentence of each paragraph.
Users tend to skim the first one or two sentences of each paragraph when scanning text.
Descriptive first sentences set the tone for each of these paragraphs, and provide users with an understanding of the topic of each section of text.
Bailey, Koyani and Nall, 2000; Lynch and Horton, 2002; Morkes and Nielsen, 1997; Morkes and Nielsen, 1998; Spyridakis, 2000.
Limit the Number of Words and Sentences
To optimize reading comprehension, minimize the number of words in sentences, and the number of sentences in paragraphs.
To enhance the readability of prose text, a sentence should not contain more than twenty words. A paragraph should not contain more than six sentences.
Bailey, 1996; Bailey, Koyani and Nall, 2000; Bouma, 1980; Chervak, Drury and Ouellette, 1996; Evans, 1998; Kincaid, et al., 1990; Marcus, 1992; Mills and Caldwell, 1997; Nielsen, 1997c; Palmquist and Zimmerman, 1999; Rehe, 1979; Spyridakis, 2000; Zimmerman and Clark, 1987.
Use Active Voice
Compose sentences in active rather than passive voice.
Comments: Users benefit from simple, direct language. Sentences in active voice are typically more concise than sentences in passive voice. Strong verbs help the user know who is acting and what is being acted upon. In one study, people who had to interpret federal regulation language spontaneously translated passive sentences into active sentences in order to form an understanding of the passages.
Active voice: John hit the baseball
Passive voice: The baseball was hit by John
Flower, Hayes and Swarts, 1983; Horton, 1990; Palermo and Bourne, 1978; Palmquist and Zimmerman, 1999; Redish, Felker and Rose, 1981; Smith and Mosier, 1986; Spinillo and Dyson, 2000/2001; Spyridakis, 2000; Wright, 1977; Zimmerman and Clark, 1987.
Do not use words that typical users may not understand.
Comments: Terminology plays a large role in the user’s ability to find and understand information. Many terms are familiar to designers and content writers, but not to users. In one study, some users did not understand the term ’cancer screening’ Changing the text to ’testing for cancer’ substantially improved users’ understanding.
To improve understanding among users who are accustomed to using the jargon term, it may be helpful to put that term in parentheses. A dictionary or glossary may be helpful to users who are new to a topic, but should not be considered a license to frequently use terms typical users do not understand.
Cockburn and Jones, 1996; Evans, 1998; Horton, 1990; Mayhew, 1992; Morkes and Nielsen, 1997; Morkes and Nielsen, 1998; Nall, Koyani and Lafond, 2001; Schramm, 1973; Spyridakis, 2000; Tullis, 2001; Zimmerman and Prickett, 2000; Zimmerman, et al., 2002.
Use Familiar Words
Use words that are frequently seen and heard.
Comments: Use words that are familiar to, and used frequently by, typical users. Words that are more frequently seen and heard are better and more quickly recognized. There are several sources of commonly used words (see Kucera and Francis, 1967 and Leech et al., 2001 in the Sources section).
Familiar words can be collected using open-ended surveys, by viewing search terms entered by users on your site or related sites, and through other forms of market research.
Sources: Furnas, et al., 1987; Kucera and Francis, 1967; Leech, Rayson and Wilson, 2001; Spyridakis, 2000; Whissell, 1998.
Use Mixed Case with Prose
Display continuous (prose) text using mixed upper- and lowercase letters.
Reading text is easier when capitalization is used conventionally to start sentences and to indicate proper nouns and acronyms. If an item is intended to attract the user’s attention, display the item in all uppercase, bold, or italics. Do not use these methods for showing emphasis for more than one or two words or a short phrase because they slow reading performance when used for extended prose.
Breland and Breland, 1944; Engel and Granda, 1975; Mills and Weldon, 1987; Moskel, Erno and Shneiderman, 1984; Poulton and Brown, 1968; Smith and Mosier, 1986; Spyridakis, 2000; Tinker and Paterson, 1928; Tinker, 1955; Tinker, 1963; Vartabedian, 1971; Wright, 1977.
Reading text is easier when capitalization is used conventionally to start sentences and to indicate proper nouns and acronyms. If an item is intended to attract the user’s attention, display the item in all UPPERCASE, bold, or italics. Do not use these methods for showing emphasis for more than one or two words or a short phrase because they slow reading performance when used for extended prose.
READING TEXT IS EASIER WHEN CAPITALIZATION IS USED CONVENTIONALLY TO START SENTENCES AND TO INDICATE PROPER NOUNS AND ACRONYMS. IF AN ITEM IS INTENDED TO ATTRACT THE USER’S ATTENTION, DISPLAY THE ITEM IN ALL UPPERCASE, BOLD, OR ITALICS. DO NOT USE THESE METHODS FOR SHOWING EMPHASIS FOR MORE THAN ONE OR TWO WORDS OR A SHORT PHRASE BECAUSE THEY SLOW READING PERFORMANCE WHEN USED FOR EXTENDED PROSE.
Make Action Sequences Clear
When describing an action or task that has a natural order or sequence (assembly instructions, troubleshooting, etc.), structure the content so that the sequence is obvious and consistent.
Comments: Time-based sequences are easily understood by users. Do not force users to perform or learn tasks in a sequence that is unusual or awkward.
Studies have shown that using “Dictionary” instead of “Glossary” provides much more positive feedback for your typical user.
Sources: Czaja and Sharit, 1997; Farkas, 1999; Krull and Watson, 2002; Morkes and Nielsen, 1998; Nielsen, 2000; Smith and Mosier, 1986; Wright, 1977.
Define Acronyms and Abbreviations
Do not use unfamiliar or undefined acronyms or abbreviations on Web sites.
Acronyms and abbreviations should be used sparingly and must be defined in order to be understood by all users. It is important to remember that users who are new to a topic are likely to be unfamiliar with the topic’s related acronyms and abbreviations. Use the following format when defining acronyms or abbreviations: Physician Data Query (PDQ). Acronyms and abbreviations are typically defined on first mention, but remember that users may easily miss the definition if they scroll past it or enter the page below where the acronym or abbreviation is defined.
Ahlstrom and Longo, 2001; Evans, 1998; Morrell, et al., 2002; Nall, Koyani and Lafond, 2001; Nielsen and Tahir, 2002; Tullis, 2001.
Use Abbreviations Sparingly
Show complete words rather than abbreviations whenever possible.
The only times to use abbreviations are when they are significantly shorter, save needed space, and will be readily understood by typical users. If users must read abbreviations, choose only common abbreviations. However – if an abbreviation is not in common usage (DARS, DFARS, AKSS), the complete title should be used.
Ahlstrom and Longo, 2001; Engel and Granda, 1975; Evans, 1998; Smith and Mosier, 1986.
Write Instructions in the Affirmative
As a general rule, write instructions in affirmative statements rather than negative statements.
When giving instructions, strive to tell users what to do (see a dentist if you have a toothache), rather than what to avoid doing (avoid skipping your dentist appointment if you have a toothache). If the likelihood of making a wrong step is high or the consequences are dire, negative voice may be clearer to the user.
Greene, 1972; Herriot, 1970; Krull and Watson, 2002; Palmquist and Zimmerman, 1999; Smith and Mosier, 1986; Wright, 1977; Zimmerman and Clark, 1987.
Limit Prose Text on Navigation
Do not put a lot of prose text on navigation pages.
When there are many words on navigation pages, users tend to rapidly scan for specific words or begin clicking on many different links, rather than reading the text associated with the links.
Bailey, Koyani and Nall, 2000; Evans, 1998; Morkes and Nielsen, 1998; Nielsen, 2000; Spyridakis, 2000.