Impact of semantic aids on command memorization for on-body interaction and directional gestures

Previous studies have shown that spatial memory and semantic aids can help users learn and remember gestural commands. Using the body as a support to combine both dimensions has therefore been proposed, but no formal evaluations have yet been reported. In this paper, we compare an on-body interaction technique (BodyLoci) to mid-air Marking menus in a virtual reality context. We consider three levels of semantic aids: no aid, story-making, and story-making with background images. Our results show important improvement when story-making is used, especially for Marking menus (28.5% better retention). Both techniques performed similarly without semantic aids, but Marking menus outperformed BodyLoci when using them (17.3% better retention). While our study does not show a benefit in using body support, it suggests that inducing users to leverage simple learning techniques, such as story-making, can substantially improve recall, and thus make it easier to master gestural techniques. We also analyze the strategies used by the participants for creating mnemonics to provide guidelines for future work.