In going through the literature, there appeared to be two patterns of empirical studies, those I will call human factor studies, and those that appear to be more broad-based software engineering, The first class includes studies aimed at understanding the human cognitive process, e.g., how individual programs perceive or solve problems. The second set of studies appear to be aimed more at understanding how to aid the practitioner, i.e., building models of the software process, product and their relationship. We will call the project-based studies. The reason for making the distinction is that they appear to have different patterns. Many of the h- factor studies were done by or with cognitive psychologists who were comfortable with the experimental paradigm. The object of study tended to be small, the purpose was evaluation with respect to some performance measure. The point of view was mostly the researcher, attempting to understand something about programming.