This is a simple flat structure of individuals instantiating roles, but the grapher allows this basic grid structure to be extended to hierarchical relations. Sisyphus is research program to encourage international collaboration in knowledge-based system development initiated by the European Knowledge Acquisition Workshop in 1989. At the top, Figure 30 shows the top level conceptual structures of an organizational domain, and at the bottom, the assertion of facts about a particular organization. Human-computer interaction in the editor is modeled on Apple's MacDraw with additional features appropriate to the language, such as arcs remaining attached to nodes when they are dragged. A popup menu as shown at the bottom of Figure 30 allows connecting lines to be entered easily.
Updates are efficient and graphs with over a thousand nodes can be manipulated interactively.
However, partitioning data structures over several screens is encouraged, and has proved practical in managing large knowledge structures. The grapher interface to the knowledge representation server allows the knowledge structures to be used deductively to solve problems and give advice. Other programs such as HyperCard can also access the server and provide additional functionality, such as customizable end-user interfaces. Repertory grid data and induced rules, elicited and analyzed through the KSS0-style modules, may be exported to the grapher for visual analysis and editing. Thus KSSn is a step towards a new family of tools that instantiate more aspects of personal construct psychology than those based on repertory grids alone.