Lists: Open vs. Drop-Down (Draft)
HHS shall use open lists i.e. items listed in full (see example) rather than drop-down lists to select one from many. However, if a list is extremely long, such as in a list of states and territories, a drop-down list is acceptable. Drop down lists should be ordered logically (A to Z, etc.).
Generally, the more items users can see in a list (without scrolling), the faster their responses will be, and the fewer omission errors they will make. Ideally, users should be able to see all available items without scrolling.
Open lists tend to elicit faster performance primarily because drop-down lists require an extra click to open. The available research does not indicate the upper number limit of items that should be displayed in a list.
Bailey, 1996; Fowler, 1998; Marcus, Smilonich and Thompson, 1996.
Requirements (content & style):
Screen-based controls (widgets) (V2, 13:21, p. 139)
Use open lists to select one from many.