A Comparative Study of Flowcharts and Program Design Languages for the Detailed Procedural Specification of Computer Programs

Abstract : An experiment was performed to assess the relative merits of Program Design Languages (PDLs) and flowcharts as techniques for the development and documentation of detailed designs for computer programs. Twenty students in a computer science graduate course participated in this experiment. Working individually, the students designed a two-pass assembler for a simple minicomputer. Half the students expressed their design for the first pass of the assembler in the form of a flowchart, and expressed their design for the second pass in a Program Design Language. The other half of the students used a PDL for pass one, and a flowchart for pass two. Flowcharts and PDLs were compared on the basis of various measures of overall design quality, design errors, level of detail of designs, time expended in developing designs, and subjective preferences. Overall, the results suggest that software design performance and designer-programmer communication might be significantly improved by the adoption of informal Program Design Languages, rather than flowcharts, as a standard documentation method for detailed computer program designs.