Reviewer: Hector A. Villa-Martinez

In this paper the authors challenge the “assumption that usability is a concept that applies only to the ultimate consumers of information technology” and examine the usability of the representations utilized by systems developers. They compare the traditional process-oriented (PO) approach with the object-oriented (OO) approach. The authors examine the usability of the OO representations with 3 experiments. In the first study they try to establish if there is a correlation between the nature of the task (OO or PO) and the tool (OO or PO) utilized to model the task. In the second study they examine if the modeler’s prior experience affects the usability of OO representations. In the third study they try to determine, given one OO representation and one PO representation of the same task, which one is easier to interpret. In the last part, the authors offer some interesting conclusions. They find that in novice developers there is a correlation between the nature of the task and the modeling tool. That modeler’s with prior PO experience doesn’t find OO approach more usable, and that the PO representation is easier to comprehend than the OO representation. The paper is well written and its main contribution is it finds that the OO model is not a “silver bullet”[1]. The authors recognize its value but recommends caution to enterprises thinking to switch from a PO model to a OO model. [1] Brooks, F. P. The Mythical Man-Month. Anniversary Edition. Addison-Wesley, Reading, Mass., 1999.