Effects of language fluency and graphic animation on modality choices by adults when following online explanatory demonstrations

This study examined the combinations of audio, text, and graphics that 96 paid adult volunteers selected when they followed an online demonstration of setting an alarm on a virtual cellphone on a touch-screen. The volunteers either had English as their first language (E
^1st
) or not (E
^2nd
), or were adults who were native English speakers but considered themselves poor readers (PR). The demonstration was divided into nine subgoals through which participants proceeded at their own pace. For half the volunteers the actions within each subgoal were animated, and for half they were labeled on a static graphic. Task accuracy ( > 90% correct) and speed were similar across fluency groups. Most people combined modalities (E
^1st
63%, E
^2nd
69%, PR 72%), and the less fluent readers (E
^2nd
and PR) included voice more often than E
^1st
(p < 0.05). E
^1st
most often chose graphic+text, whereas PR chose graphic+voice (listening preferred to reading), and E
^2nd
chose graphic+text+voice (listening helped their reading). Animation changed the pattern of modality combinations, increasing selection of graphic+voice at the expense of graphic+text (p < 0.05). These data suggest that many members of the public will differ from designers in their modality preferences, making it desirable to incorporate modality choices into online explanatory demonstrations.