List Box, Single-selection

1. List Box, Single-selection • Making the user select one item from a list of 6+ • an alternative to radio buttons • not good for • the list is not yet complete or well-defined • space is limited: use a drop-down list box instead • Guidelines • provide some clue showing only one can be selected • “Select one of [these items]” • make sure all items can be viewed horizontally • note the limits of the development package • usability test: make sure that no items need to be added

2. List Box, Multiple-selection • Good for • select 1+ item from a long and possible dynamic list • an alternative to check boxes, if options change often • not good for • situations when space is limited • users may need to enter new items • situations that could be done better graphically • data-entry application • Guidelines • restrict to large functions like opening files • keep in dialog boxes rather than on main windows • the part of the list seen should be about 7, can 10-20

3. MS List Box Guidelines • Make the user’s choices obvious • selection summary box or check box/listbox component • on a scrolled list, add a label that says how many items • How to organize lists • alphanumeric order: exact word or label • categorical order: answer to a question • let users rearrange the list, done by turning column headings into sort toggle buttons • searching lists electronically: filters or a real search • Usability test: affordability, sort orders, search option or filters

4. Combo Box • A combination of a list box and a text-entry area • text-entry can have searching functions • not good for • select more than one item at a time • fewer than 5 items • Three styles • simple combo box: whenever enough space • drop-down combo box: limited space • drop-down list box

5. Combo Box Guidelines • Searching • useful when the list is long • Data entry • do not force to pick items if list incomplete • wrong spelling might damage data integrity • check the task analysis • Usability: make sure users know can type + select