Performance metrics for document understanding systems

Requirements for the objective evaluation of automated data-entry systems are presented. Because the cost of correcting errors dominates the document conversion process, the most important characteristic of an OCR device is accuracy. However, different measures of accuracy (error metrics) are appropriate for different applications, and at the character, word, text-line, text-block, and document levels. For wholly objective assessment, OCR devices must be tested under programmed, rather than interactive, control