#9 Combo / select boxes for long option lists

[Richard Mitchell]

"In the case of multiple-choice and likert scale questions, it is possible that a researcher will wish to specify a very large number of options. It would be desirable to provide researchers with a means of allowing users to select a single or multiple options from a long list, without too many being displayed at once. This would prevent questionnaires from being unreasonably long, requiring an excessive amount of scrolling on the part of the participant, and would assist the participant in reading and understanding the list. A reasonable way to achieve this would be by using a select, combo or list box GUI widget; the first two being cases where a single item could be selected and the last allowing either single or multiple selections."

~ Mitchell, R. (2008)