Lists

Lists are commonly found on Web sites.These may be lists of, for example, people, drugs, theaters, or restaurants. Each list should be clearly introduced and have a descriptive title. A list should be formatted so that it can be easily scanned. The order of items in the list should be done to maximize user performance, which usually means that the most important items are placed toward the top of the list. If a numbered list is used, start the numbering at 'one,' not 'zero.' Generally only the first letter of the first word is capitalized, unless a word that is usually capitalized is shown in the list.

Order Elements to Maximize User Performance:

• Arrange lists and tasks in an order that best facilitates efficient and successful user performance.
• Designers should determine if there is an order for items that will facilitate use of the Web site. If there is, ensure that the site is formatted to support that order, and that all pages follow the same order. For example, ensure that lists of items, sets of links, and a series of tabs are in a meaningful order.
• Where no obvious order applies, organize lists alphabetically or numerically. Keep in mind that it is the user's logic that should prevail rather than the designer's logic.

Place Important Items at Top of the List:

• Place a list's most important items at the top.
• Experienced users usually look first at the top item in a menu or list, and almost always look at one of the top three items before looking at those farther down the list. Research indicates that users tend to stop scanning a list as soon as they see something relevant, thus illustrating the reason to place important items at the beginning of lists.

Format Lists to Ease Scanning:

• Make lists easy to scan and understand.
• The use of meaningful labels, effective background colors, borders, and white space allow users to identify a set of items as a discrete list.

Display Related Items in Lists:

• Display a series of related items in a vertical list rather than as continuous text.
• A well-organized list format tends to facilitate rapid and accurate scanning. One study indicated that users scan vertical lists more rapidly than horizontal lists. Scanning a horizontal list takes users twenty percent longer than scanning a vertical list.

Introduce Each List:

• Provide an introductory heading (i.e., word or phrase) at the top of each list.
• Providing a descriptive heading allows users to readily understand the reason for having a list of items, and how the items relate to each other. The heading helps to inform users how items are categorized, or any prevailing principle or theme. Users are able to use lists better when they include headings.

Use Static Menus:

• Use static menus to elicit the fastest possible speed when accessing menu items.
• To elicit the fastest possible human performance, designers should put the most frequently used menus times in the first few positions of a menu. Designers should determine the location of items within a menu based on the frequency of use of each item. Adaptable menus, where users are allowed to change the order of menu items, elicits reasonably fast performance as well. The slowest performance is achieved when an adaptive menu, where the computer automatically changes the position of menu items, is used. One study found that users prefer having static menus, rather than adaptive menus.

Start Numbered Items at One:

• When items are numbered, start the numbering sequence at 'one' rather than 'zero.'
• Do not start the numbering with a 'zero.' When counting, people start with 'one,' not 'zero.'

Use Appropriate List Style:

• Use bullet lists to present items of equal status or value, and numbered lists if a particular order to the items is warranted.
• Bullet lists work best when the items do not contain an inherent sequence, order, or rank. Numbered lists assign each item in the list an ascending number, making the numerical order readily apparent. Numbered lists are especially important when giving instructions.

Capitalize First Letter of First Word in Lists:

• Capitalize the first letter of only the first word of a list item, a list box item, check box labels, and radio button labels.
• Only the first letter of the first word should be capitalized unless the item contains another word that would normally be capitalized.

Source:[usability.gov]