Extending the spreadsheet interface to handle approximate quantities and relationships
Clayton Lewis · ACM SIGCHI Bulletin · 1985
Conventional spreadsheet programs offer a very convenient user interface for many quantitative tasks, but they are restricted to handling precisely-specified quantities and calculations. ASP is a generalized spreadsheet that extends the basic spreadsheet paradigm to encompass quantities which are not known exactly, and functions which are not known well enough to permit calculation. ASP works by propagating assertions about quantities and functions through the network of relationships that the spreadsheet defines.