PEOPLE AND MACHINES?

What I'm talking about is how people and machines interact. This is often referred to as "Human-Computer Interaction" (HCI) or "Computer-Human Interaction" (CHI), especially by people who approach the issue from a traditional computer science perspective or Human Factors perspective.

There are a number of emerging roles which often overlap and which struggle with definitions and labels. I'll review a few of these and provide my take on how these terms are generally defined and what they mean to me, but understand that others may define job titles, roles and responsibilities differently.

USABILITY

Usability professionals, often trained in psychology or ergonomics, focus on analyzing ideas, systems and products through user testing, or through expert evaluation based on experience in user testing. The king of the usability gurus is Jakob Nielson, although my affinity for psychology leads me to prefer the writings of his partner, Don Norman, who describes usability:

The field of usability design takes root in the cognitive sciences -- a combination of psychology, computer science, human factors, and engineering. These are all analytical fields. The discipline prides itself on its scientific basis and experimental rigor. (source)

Nielson's site is optimized for usability but often criticized on aesthetic grounds; this highlights a difference between usability analysts and designers. However, it is worth noting that some practitioners have leveraged this perspective to design solutions, rather than simply testing and analyzing existing designs. And Norman also points out, "the hidden danger [of usability design] is to neglect areas that are not easily addressed in the framework of science and engineering." The Usability Professionals Association is a source for additional information.

INTERFACE DESIGN

Interface design is one area where roles and definitions become blurred. Interaction Designers and Information Architects sometimes consider Interface Design to be focused primarily on graphic design for user interfaces. I don't think this necessarily reflects all cases, but it is likely rooted in traditional software development practices, where interface design has been focused on the presentation layer and may even be left to the end of the development process, when it is too late to substantially influence system behavior. I believe that proper Interface Design should really have the scope of Interaction Design. A traditional stronghold of HCI, the ACM's SIG-CHI has shown itself to be broad and progressive (check out the sigchi bulletin).

INTERACTION DESIGN

Interaction Design, as I see it, is an umbrella role, extending across the user experience. Interaction Design should ideally be integrated throughout the planning and design process, involved with requirements analysis and system design. While some consider Interface Design to be focused on details of appearance and screen layout, Interaction Design concerns itself with functionality and flow of the the system, leveraging Usability, Interface Design and potentially Information Architecture to achieve an integrated User Centered Design process. There is an active forum for interaction designers at the Interaction Design Group.

INFORMATION ARCHITECTURE

The term "Information Architecture" is generally attributed to Richard Saul Wurman's usage in the mid-1970's. Like me, Wurman came to "Information" from the perspective of traditional (physical) architecture. Wurman used the term primarily to describe the practice of presenting information in a way that was easy to understand and use, with an emphasis on graphic design (closer to what some would call Information Design).

Later, the term was popularized (some claim "usurped") by Louis Rosenfeld and Peter Morville, with their book, Information Architecture for the World Wide Web (referred to as "the Polar Bear Book", based on O'Reilly's cover art). Rosenfeld and Morville were trained in library science, and their approach focuses largely on categorizing, labeling, structuring and cataloging information. The AIfIA is a professional organization for information architects and there is a lively forum on the sigia-l list.

You might want to take a look at my reading list for relevant books. Or check out the goings-on at ok-cancel. Also, Terry Winograd teaches an Introduction to HCI at Stanford University and the itinerary is available online.