Among UI patterns, the accordion menu is a workhorse. Its ability to collapse long lists into manageable groups is really useful for navigation menus and particularly for search filters. Beyond the decision to use an accordion menu, I often find the specifics of actually designing one to be a little murky. What icon should I use? Should the icon go on the left or right of the menu item? In terms of usability, is an icon really necessary at all?
Seeking some certainty on these questions, I decided to do some testing.