Tuesday, September 22, 2009

Tools for Aligning Mental Models with Conceptual Models

As HCI professionals, a major goal is for our users to construct mental models that are closely aligned with our conceptual design models. If the two models match up, the users will understand the system and how to use it. We typically don't speak directly with the users, so our only means of communicating the system is through what Norman refers to as the “System Image”. The system image is comprised of the user interface as well as any other artifacts related to the system (e.g. - user manuals and training materials). Therefore, in order to meet our goal, we must construct an appropriate and functionally accurate system image for our users.

To construct the system image, it is important to (1) understand our users and (2) understand the tasks our users need to perform. The reading material from this week describes methods for understanding users. We can leverage ideas from Light and Wakeman to understand how users perceive certain aspects of the system interface in regards to awareness. We can also leverage the differential psychology theories mentioned in Dillon and Watson to understand our users' cognitive abilities. In understanding users' tasks, task analysis and requirements elicitation methods can be utilized. Furthermore, a lot of work has been done on the application of cognitive task analysis to draw out tacit knowledge that users may hold about their business processes.

Beyond the Interface
In “Beyond the Interface”, Light and Wakeman present results of a study to measure user behavior and thought processes during website interaction. The authors’ intent is to describe how the process of interacting with websites brings about two levels of awareness in the user: (1) awareness of the interface, and (2) awareness of the social context beyond the interface. The study is grounded in HCI theories that place focus on using the Web as a medium for communication, rather than using it as a tool for problem solving. Perhaps one of the most important theories suggests user interactions follow similar rules to the “turn taking of spoken engagement”. When these rules are violated, users have a hard time understanding the behavior of the software. Another theory leveraged in the study deals with the idea of “ritual constraints”. “Ritual constraints” are social rules inherent in the nature of human interaction. Here, the user is cognizant of the implication of his or her acts, specifically, how the acts are interpreted by others in the social setting.

The study revealed the main point regarding user awareness. Users are aware of the two levels of interaction, one with the interface, and one with the recipients behind the interface. The second awareness seemed to present itself when users were actually entering data/interacting with the website, as apposed to simply navigating the website. The corollary is the importance for developers to adopt a communication metaphor when creating interactive components on a website. The study revealed another interesting point regarding the user’s perception of the recipients of inputted data. Recipient identity is constructed from a combination of the user’s expectations of a commercial brand, the user’s experience with interactive portions of the site, and the user’s purpose in visiting the site.

The paper concludes with recommendations on how to apply the findings of the study. The findings suggest that interactive websites would benefit from: proper identification of the recipient of the user’s data (especially if the data is personal in nature), confirmation pages after the entry of data, statements about how the recipients will use the submitted data, and an explanation of why the recipient is collecting data that does not appear to assist in the completion of the user’s task.

User Analysis in HCI
In their paper, Dillon and Watson assert that user analysis in HCI can benefit from the application of differential psychology research. User analysis is normally relegated to understanding users in general terms such as educational background and technical expertise. (Nielsen's three dimensional analysis of users is cited.) The authors argue that such general user analysis is highly context sensitive and it does not offer solutions that can satisfy unique users/user groups. The aim of differential psychology is to understand user behavior and specific aptitudes of users such as memory, perceptual speed and, deductive reasoning.

Dillon and Watson go on to describe studies of how work done in differential and experimental psychology was leveraged directly in the design of user interfaces. One study focused on logical reasoning, the other on visual ability. They concluded that appropriate design of the interfaces/training material can reduce discrepancies in cognitive abilities amongst users.

I think it's apparent how we can apply the ideas in both papers mentioned above. They demonstrate not only how users think, but what users think when engaged in discourse with interactive web applications. Also demonstrated is how this knowledge can be applied directly to user interface design. I think the idea of the “conversation” with the system is a huge factor when measuring how closely the user's mental model matches up with the conceptual design model. I believe its the best way we can describe software systems. After all, “conversations” define software use cases, and software use cases define a system.

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