Requirements for graphical front ends for visual languages

Although great progress has been made in the development of visual languages, little attention has been paid to how diagrams in such languages should be entered into computers. This issue will have a great impact, however, on users´ acceptance of visual languages. We present an analysis of the features of visual languages influencing diagram entry, and also the results of an experiment comparing users´ performance on different types of diagram editors. This data is then used to suggest design guidelines for usable visual language front ends