ICS 463: Intro to Human Computer Interaction Design

2. User-Centered DesignDan 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

• Requirementscan be identified

• Representations used canadequately 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:

Analysis

AnalysisDesign

Implementation

Design

Implementation

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 1999• http://www.foruse.com/

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 salientNeeds change throughout the design

process: => range of representations