Within the field of human computer interaction (HCI) an icon is a "graphic on a visual display terminal that represents a function of the computer system" (European Telecommunications Standards Institute (ETSI), 2002, p.17). Icons are either pictograms that communicate the likeness of a real world object by abstracting and simplifying (folders, documents, the envelope for email, the magnifying glass for search), or an attempt to communicate a function (the X for close, arrows for back and forward), or sometimes a combination of the two. When using well-established conventions, even if the visual is abstract (such as the three lines for a menu on mobile devices) icons can be a direct route to user understanding. Within both LAWA and Making Good both pictograms and variations on symbols have been used. Careful consideration of conventions and peer testing has determined that the icons are either established and extensively used elsewhere, or, if unfamiliar, not misleading and able to be interpreted through visual and functional cues.