For over two decades, software psychology researchers have been developing insights to software productivity and quality by investigating builders and users of software. This research has been diverse in both its approach and its impacts. It has introduced systematic behavioral measurement into the software development process and into research on new software techniques and technologies, and has also opened up new social and cognitive interpretations of software processes [5, 12]. We now see evidence of a new thrust in software psychology coming to the fore, one in which usability researchers are direct participants in the definition and creation of new software artifacts. We call this paradigm Ecological Design, to emphasize (1) that realistic software situations are being confronted on their own terms, and (2) that the work is directed toward design results, not merely toward evaluation and description in the service of design goals. The reorientation towards studying teamwork was prompted in 1971 by Weinberg and followed by a few researchers at that time, but the movement has accelerated with the recent and intense interest in computer supported collaborative work . This was apparent in the papers presented at the two workshops on Empirical Studies of Programmers [10, 13]. An accompanying shift has also occurred in the software engineering community. The traditional waterfall model of software development with the precise specification of a provable topdown design is giving way to newer exploratory styles of program development that emphasize rapid prototyping and iterative refinement. The shift from product to process also puts greater emphasis on team organization, group processes, management policies, reusability, development tools, design methods, debugging strategies, and maintenance . The three papers in this special section exemplify this new paradigm. Rosson, Maass, and Kellogg and Curtis, Krasner, and Iscoe describe highly qualitative studies of professional designers that produced specific technical proposals for improving software tools and the coordination of project management, an assessment of major bottlenecks, and a new framework for thinking about software design as a learning and communication process. Soloway, Pinto, Letovsky, Littman, and Lampert describe the design and exploration of software documentation that grew out of similarly qualitative studies of program maintenance. We caution that this research paradigm is still in its infancy: setting design requirements and developing prototypes are not traditional activities of psychological researchers. These roles are still emerging, still being reconciled with the earlier paradigms. The particular projects highlighted here are only the beginning; the field continues to evolve, as more researchers are attracted, as more topics are explored, as more methods are developed. Thus, despite the shortcomings of any particular project, the trajectory of this paradigm seems clear to us: it is the development of ideas that directly impact productivity and quality in software. Indeed, part of our intention in presenting this special section is to encourage more and more rapid development of the new paradigm. © 1988, ACM. All rights reserved.