pucd

Principles of User-Centered Design: 

Principles of User-Centered Design CSCI 4800/6800 Feb. 1, 2006

What is design? : 

What is design? Finding the right components of a physical structure A goal-directed problem-solving activity Simulating what we want to make or do before we make or do it – as many times as may be necessary to feel confident in the final result Engineering design: “the use of scientific principles, technical information and imagination in the definiton of a mechanical structure, machine or system to perform pre-specified functions with the maximum efficiency and economy.

Approaches : 

Approaches Formal specifications Custom crafted / creative

User-Centered Design: 

User-Centered Design Principles Make user issues central in the design process Carry out early testing and evaluation with users Design iteratively

Methods for UCD: 

Methods for UCD Soft Systems Methodology (SSM) Open Systems Task Analysis (OSTA) Multiview Star Life Cycle

Soft Systems Methodology: 

Soft Systems Methodology Focuses on planning Approach developed by Checkland, Schloes ’81, ’91 Emphasis : understand the problem and its situation

SSM: 

SSM

Stages in SSM: 

Stages in SSM Stages 1 and 2 – obtain “rich expression” of the problem: meetings with stakeholders Stage 3 – obtain precise definition of the system Stage 4 – produce conceptual models: abstract representation, “root definition”

SSM, “root definition”: 

SSM, “root definition” C - Clients (people who will benefit/suffer) A - Actors (who is involved with system) T - Transformation (purpose) W - Weltanschauung/World View (perspective from which root definition is formulated) O - Owners (who has commissioned system) E - Environment

SSM: 

SSM Stage 5 – compare “root definition” of stage 4 with “rich expression” of stage 2; iterate until gaps are filled Stage 6 – identify changes Stage 7 – recommend an action

SSM: 

SSM Benefits for HCI engineering: Identifies people, constraints, view of system Develops conceptual models

Cooperative Design: 

Cooperative Design Participative design – users participate in design process Sociotechnical design – considers both social and technical alternatives/solutions to/ aspects of problems OSTA – Open Systems Task Analysis (Eason, Harker ’89)

OSTA: 

OSTA

OSTA: 

OSTA Specified together: Technical requirements System structure, functionality Social system requirements Usability, acceptability Goal: Provide method for understanding what occurs when computer system is introduced into a working environment

OSTA – Systems Analysis (top): 

OSTA – Systems Analysis (top) Primary task stated (goals of group of workers identified) Task inputs identified - usually come from outside the system - character of inputs may vary & affect way system behaves External environment - including physical environment, economic, political conditions, demand for task output Transformation processes described typically - object/action flowchart of objects to be transformed & actions neccessary to transform them with annotations

OSTA – technical and social: 

OSTA – technical and social 5. Social system analyzed Roles of people in relation to one another Characteristics & qualities of users of new system Technical system analyzed - how will new system be integrated with others systems & what remains of the old system? Performance satisfaction – for social system under new technical systems Requirements for new technical system, based on the task analysis Functionality, usability, acceptability

Problems:: 

Problems: Need expert to guide the design process Ability to integrate with other design processes/methods Need “right” organizational and political climate Cost-effective???

Multiview: 

Multiview Combines sociotechnical and soft-systems approaches Stage 1: create PTM (primary task model) – similar to “root def” Stage 2: conceptual modeling of info flows/ structure, produce FM (functional model), ER model, dataflow models Stage 3: design people tasks (PT), role sets (RS), and computer task requirements (CTR) Stage 4: design the HCI Stage 5: technical design

Multiview: 

Multiview

Multiview: 

Multiview Provides more direction for system designers

Star Life Cycle: 

Star Life Cycle No prescribed ordering of activities Based on actual design practive of HCI designers Emphasis on prototyping and evaluation Rapid prototyping, incremental development

The Star Life Cycle: 

The Star Life Cycle

Star Life Cycle: 

Star Life Cycle Conceptual design – what is required? What should system do? What data is required? What will users need to know? Physical design (formal design) : how to achieve the conceptual design …

Methods for UCD: 

Methods for UCD

Example: Olympic Messaging Service (1984 Los Angeles Olympic Games) : 

Example: Olympic Messaging Service (1984 Los Angeles Olympic Games) Kiosks at which athletes could send & receive voice messages among themselves Or people from around the world could send messages in to athletes & official Twelve languages (no translation)

OMS - Process: 

OMS - Process Paper scenarios of user interface prepared Comments from designers, management, prospective users Some functions altered, others dropped Brief user guides prepared, tested, developed iteratively (~200 iteratives) Simulations constructed & evaluated; help messages designed Simulations tested with users

OMS - Process: 

OMS - Process Needed to add undo/backup button Visit to village site, demos & interviews with ex-olympians & others involved Prototype developed & tested "Hallway" method to collect info on height & layout of prototype kiosk "Try-to-destroy-it" tests of robustness (CS students)

OMS – summary : 

OMS – summary Focus on users & tasks early in design process, including user guides, help, & ensuring that user's cognitive, social, & attitudinal characteristics are understood & accomodated Measure reactions by using prototype manuals, interface, & other simulations of the system Design iteratively All usability factors must evolve together and be under the responsibility of one control group

Example: Air Traffic Control System: 

Example: Air Traffic Control System Original system Variety of info needed, each from own source - some on desk, some on ceiling, some not in line of sight Dials Closed Circuit TV Temporary instructions

Air Traffic Control: 

Air Traffic Control Desire: Integrated data display system SAFETY (major concern) "Upgradeable" Variety of airports/local requirements Modified info requirements Layouts specific to controller & task More color Ability to add pages for specific local conditions Simple editing facilities for updates

Example – Air Traffic Control System: 

Example – Air Traffic Control System Process: Evaluate controller’s task Develop first-cut design Establish user-systems design group Concept testing, user feedback Produce upgraded prototype Road-show to five airports Develop systems specification build and install system establish new needs