Guidelines for Reducing Human Errors in the Use of Coded Information

Abstract

This paper presents code design and display guidelines intended to make it difficult to generate a code-related error and easy to detect errors that still occur. Principles governing immediate memory and rules for making erroneous codes easily recognizable combine to form guidelines for code design. Design factors include various dimensions of code configuration-length, the kind of characters, their location and grouping. These guidelines minimize the common errors of substitution, transposition, omission, and addition of characters. Besides the code itself, errors are also affected by the way the code is displayed. To further enhance reliability, additional guidelines are included for the size, style, and contrast of characters. A reliable code system requires a structure which is compatible with human recognition and short-term memory capabilities. These abilities have been extensively explored in the experimental psychology literature. The particular studies used as a basis for the code guidelines in this paper are those where recall follows perception by only a few seconds and no intervening information is processed in the interim. These experimental conditions correspond to usual transactions in which transcription or keypunching closely follows visual perception of the code.