ICS 463: Intro to Human Computer Interaction Design 2. User-Centered Design Dan Suthers

User-Centered Design (Gould and Lewis) Focus on users and their tasks early in the design process Measure reactions by using prototype manuals, interfaces, simulations Design iteratively Be responsible for all usability factors

Ways to be User-Centered (Gould) Visit work or installation sites Stakeholders comment on scenarios User guides written and tested in advance Simulations used to identify need for help Early demonstrations of prototypes “Hallway” testing (walk-by users) “Try to destroy it” tests

Ways to Involve Users Study them (in their situation) Ask them what they need Test designs on them Include them on the design team

Discussion of Design Methods... From Traditional to HCI Software Design Methodologies

Assumptions in Waterfall Model Requirements can be identified Representations used can adequately capture these requirements Organization does not change as result of introduction of the system

Alternative Development Models “Plan to throw one away: you will, anyway” Spiral: W:

Soft Systems Methodology “Understanding the situation in which a perceived problem is thought to lie” –Stakeholders express problem –Write root definition (CATWOE) –Build conceptual models of system –Compare models with expressed problem –Identify feasible/desirable changes –Design action to effect changes

Cooperative Design Methods Sociotechnical: understanding both the social and technical system Participative: users involved in –analyzing organizational requirements –planning social and technical structures to support individual and organizational needs OSTA

Multiview Staged methodology –Analyze human activity (primary task model) –Analyze information structure and flow (functional model) –Analyze and design sociotechnical (roles, people and computer tasks) –Design HCI –Design technical system

Star Model Ordering of activities is inappropriate Evaluation is central; prototyping important Start anywhere Based on what designers do!

Usage-Centered Design I will demonstrate an example methodology, similar to Multi-view (in ordering) and Star (in evaluation), which also illustrates the use of various representations. Constantine & Lockwood

Representations for Design “A design is an information base that describes aspects of this object, and the design process can be viewed as successive elaborations of representations, such as adding more information or even backtracking and exploring alternatives.”

Suitable Representations Accurate enough Simple enough Makes important issues salient Needs change throughout the design process: => range of representations