CSE491 Human-Computer Interaction Eileen Kraemer 8/28/07

Course content Design, implementation, evaluation of user interfaces for computer systems Take into account: human factors usability design process Topics include: effects of human capabilities and limitations on interaction with computer systems Ethics and rules for working with human subjects Experimental design and statistical analysis “New” topics in HCI

Projects.. Students will apply these concepts to the design and implementation of graphical user interfaces. Java will be used for UI design; guidelines for such use will be discussed

What do you already know?: “Folk” HCI “Folk” theories (e.g. folk psychology, folk physics) help in everyday explanations (e.g. why people do things, what will happen to cartoon character when he runs off cliff…) Folk HCI: Our intuitive knowledge about usability and explanations

However …. Folk theories are often wrong w.r.t. scientific/engineering analyses …

“Folk” definitions of usability Speed of response Regularity of response Intuitiveness Familiarity Legibility Navigability Freedom from error Expected feedback Absence of visual clutter Clear what to pay attention to.. All good ideas, but: What do they really mean? How do we achieve them?

Understanding humans Humans = sensory processors Sensory psych., EE & CS systems Humans = interpreters/predictors Cog. Psych and AI Humans = actors in environments Activity theory, ethnograpy, ecological psychology Question: How much and how rapidly do humans change?

What makes a system usable? Humans = sensory processors Usability == fit with human limits Humans = interpreters/predictors Usability == fit with knowledge Humans = actors in environment Usability == fit with task and social context

Two views of interaction Interaction with: Software system is tool or machine Interface is a usability-engineered membrane Human-as-processor and interpreter model Interaction through: Software is a medium used to interact with task objects or other people Software must make affordance visible Human-as-interpreter & -actor models

Broadening the Cognitive Framework Recent developments in cognitive psychology From human factors to human actors Cognition and action as social[Vygotsky] Distributed cognition Use of artifacts as external memories[Hutchins]

Affordances “What sort of operations and manipulations can be done to a particular object” [Norman] Examples: Handles Scroll bars Other “virtual” affordances such as icons

Good resources.. The HCI Bibliography ACM SIGCHI Curriculum for HCI First Principles of Human-Computer Interaction Online article PPT presentation

The “ideal” order of coverage: 1. Design 2. Implementation 3. Evaluation … but that would push implementation too late in the semester for you to have time to accomplish much..

Our order of coverage: Implementation Design Evaluation … on Thursday we’ll begin a rapid-fire coverage of Java. Much is quite similar to C++ so we’ll be able to move quickly.