XVIZIT: Visualizing cognitive units in spreadsheets

Spreadsheets can be large and complex and their maintenance and comprehension difficult to end-users. Large numbers of cells, complex formulae and missing documentation can impede the understanding of a spreadsheet. Comprehension assesses different levels of a spreadsheet according to a specific maintenance task, ranging from single formulae over sets of cells to complex structural patterns. These levels of abstraction are subsumed under the term cognitive unit. XVIZIT helps end-users in maintaining and comprehending spreadsheets. It guides them through a spreadsheet model: Roles of cells and sheets, similar patterns and various concepts of modularity can be explored. It uses modularization algorithms to provide conceptional decompositions of a spreadsheet model, such as equivalence classes or data modules. XVIZIT´s slice visualizations ease the evaluation of corrective modifications by showing the dependant cells. Furthermore, XVIZIT provides a number of complexity measures allowing end-users to estimate the effort to comprehend and maintain a spreadsheet.