A Keystroke Level Analysis of Manual Map Digitizing

The acquisition of digital spatial data is a key economical factor in GIS projects. Transforming analog graphic data by manual digitizing is slow and therefore extremely expensive. The work reported here investigates the possibility of applying the Keystroke-Level Model to the modeling and optimization of manual digitizing tasks. This model predicts the time it takes an experienced user to perform routine tasks on a given system. It has been applied successfully for text editing tasks. Here, its suitability for manual digitizing is being tested and additional unit tasks are determined. The suitability of the Keystroke-Level Model for manual digitizing tasks is analyzed in the context of a major national map digitizing effort. The agency responsible for topographic and cadastral mapping in Austria (Bundesamt für Eichund Vermessungswesen, BEV) is currently developing a digital cadastral map (Digitale Katastral-Mappe, DKM). Scanned cadastral maps are being manually digitized on screen in order to transform analog graphic data into digital form. The article describes the principles of the model, the design of an experiment, and encouraging first results.