PPIG 1995 - 7th Annual Workshop
Control Strategies Used By Expert Program Designers
Steve Lang, Tom Ormerod
Abstract: In this paper we report a study of four expert Prolog programmers designing and coding solutions to an enlarged version of the well-known 'signals' problem. Data are provided showing that experts adopt a predominately structured rather than an opportunistic approach to decomposing design problems. However. the structured approach they appear to adopt is not one of the generally prescribed pure top-down approaches of breadth-first or depth-first problem decomposition. Instead, expert Prolog programmers adopt what we have termed a 'children-first' approach to problem decomposition, in which the relative advantages of breadth-first and depth-first approaches are maximised whilst the disadvantages of these approaches are minimised. We also discuss causes of the few structure-divergent activities that were observed. as well as examining reasons why designers might switch between different structure-congruent strategies.