A Critique of ``An Exploratory Investigation of Programmer Performance Under On-Line and Off-Line Conditions´´

The preceding paper by Grant and Sackman, ``An Exploratory Investigation of Programmer Performance Under On-Line and Off-Line Conditions´´ is discussed critically. Primary emphasis is on this paper´s failure to consider the meaning of the numbers obtained. An understanding of the nature of an on-line system is necessary for proper interpretation of the observed results for debugging time, and the results for computer time are critically dependent on the idiosyncracies of the system on which the work was done. Lack of attention to these matters cannot be compensated for by any amount of statistical analysis. Furthermore, many of the conclusions drawn and suggestions made are too vague to be useful.