Error detection and display for graphical modeling environments

The authors discuss the error detection and display capabilities they believe are needed in visual modeling tools and describe the implementation of these capabilities in the Research Queueing Package Modeling Environment (RESQME). They describe how the interface can incrementally (i.e., while the model is being constructed) eliminate some classes of errors and detect and assist in correcting the other syntactical errors interactively as the user builds the model. They distinguish this incremental avoidance, detection, and notification of errors from the case in which a model is first completely constructed and then compiled or checked for errors in much the same way that a program written in traditional programming languages is compiled. They also distinguish this incremental error checking from a purely local checking for syntax errors, as is done by packages such as BLOCKS