Pictorial representation and metaphor in visual language design

This paper reports the results of seven different experiments, assessing th e benefit that users gain from the inclusion of pictorial features such as pictorial metaphor, visual mnemonics or support for visual imagery in visua l languages. The experiments are based on typical programming tasks such as problem solving, construction and interpretation. They employed a number o f experimental languages, including both implicit pictorial representations and explicitly verbal metaphorical explanations. The results of these expe riments indicate that special design considerations apply to visual languag es. Direct application of Graphical User Interface metaphors does not resul t in automatic improvements in usability of visual languages for typical pr ogramming tasks. Visual languages can benefit from pictorial mnemonics, but systematic explanatory metaphors (whether visual or verbal) are less usefu l than consistent presentation of language abstractions. (C) 2001 Academic Press.