Display-based problems in spreadsheets: a critical incident and a design remedy

A critical incident is reported where a discretionary user needed to partition the spreadsheet grid into an arithmetic series of blocks and apply a function to each, but was unable to devise a solution. The incident is first scrutinized to explicate the reasons for the failure. Then, a new method for progressional computation on tabular displays is described and reviewed for usability. The method increases the expressive power of cell referencing but also simplifies the notation. The spreadsheet is shown to be a surprisingly poor artefact for three classes of display-based problem.