gary marsdenslide 1university of cape town human-computer interaction - 8 prototyping gary marsden (...

Gary Marsden Slide 1University of Cape Town

Human-Computer Interaction - 8

Prototyping

Gary Marsden([email protected])

July 2002


Unit Objectives

We shall cover– Design guides– What they look like– Perils of using them

Rationale:– It is impossible for designers to be expert in all

the disciplines of HCI, so guidelines are constructed to guide non-experts in matters such as psychology, art, sociology etc.


Doing the stuff

So, you have conducted requirements analysis, read your design guides and considered the users’ mental models

It is time to actually make something

That something is a prototype– Most modern lifecycles require iteration about a

prototype


What is a prototype

Cardboard box, storyboardPiece of softwareChunk of plywood (Jeff Hawkin)Dummy box


Why Prototype?

Evaluation and feedback are central to interaction design

Stakeholders can see, hold, interact with a prototype more easily than a document or a drawing

Team members can communicate effectively You can test out ideas for yourself It encourages reflection: very important aspect of

design Prototypes answer questions, and support

designers in choosing between alternatives


What is Prototyped?

• Technical issues

• Work flow, task design

• Screen layouts and information display

• Difficult, controversial, critical areas

NOT just changing skins!


Low Fidelity

Uses a medium which is unlike the final medium, e.g. paper, cardboard

Is quick, cheap and easily changed

Examples:sketches of screens,

task sequences, etc‘Post-it’ notesstoryboards‘Wizard-of-Oz’


Wizard of Oz


Low-Fi Examples


High Fidelity

Uses materials that you would expect to be in the final product.

Prototype looks more like the final system than a low-fidelity version.

For a high-fidelity software prototype common environments include Macromedia Director, Visual Basic, and Smalltalk.

Danger that users think they have a full system…….see compromises


Compromises

All prototypes involve compromisesFor software-based prototyping maybe

there is a slow response? sketchy icons? limited functionality?

Two common types of compromise ‘horizontal’: provide a wide range of

functions, but with little detail ‘vertical’: provide a lot of detail for only a

few functionsCompromises in prototypes mustn’t be

ignored. Product needs engineering


Realising Prototypes

Taking the prototypes (or learning from them) and creating a whole

Quality must be attended to: usability (of course), reliability, robustness, maintainability, integrity, portability, efficiency, etc

Product must be engineeredEvolutionary prototyping ‘Throw-away’ prototyping


Users & Prototypes

The only way to really test the interface of a prototype is with real users

The lifecycles give us a way to feed what we discover back into the development process

The question remains of the best way of involving the users


Why Involve Users?

Expectation management – Realistic expectations – No surprises, no disappointments– Timely training– Communication, but no hype

Ownership – Make the users active stakeholders– More likely to forgive or accept problems– Can make a big difference to acceptance and

success of product


Microsoft Model

Users are involved throughout development

‘activity-based planning’: studying what users do to achieve a certain activity (task)

usability tests e.g. Office 4.0 over 8000 hours of usability testing.

internal use by Microsoft staff customer support lines


General UCD

User-centered approach is based on:– Early focus on users and tasks: directly studying

cognitive, behavioral, anthropomorphic & attitudinal characteristics

– Empirical measurement: users’ reactions and performance to scenarios, manuals, simulations & prototypes are observed, recorded and analysed

– Iterative design: when problems are found in user testing, fix them and carry out more tests


Ethnography

Understanding users’ work is significantEthnography: from anthropology

– ‘writing the culture’– participant observation

Difficult to use the output of ethnography in design

Often surprising (Pia)


Participatory Design

Rather than being observed, users are treated as equal partners

Scandinavian historyEmphasises social and organisational

aspectsBased on study, model-building and

analysis of new and potential future systems


PD in Practice - PICTIVE

Plastic Interface for Collaborative Technology Initiatives through Video Exploration

Intended to empower users to act a full participants in design

Michael Muller (nice chap)


PICTIVE

Materials used are:– Low-fidelity office items such as pens, paper,

sticky notes– Collection of (plastic) design objects for screen

and window layouts

Equipment required:– Shared design surface, e.g. table – Video recording equipment


PICTIVE Session

Before a PICTIVE session:– Users generate scenarios of use – Developers produce design elements for the

design session

A PICTIVE session has four parts:– Stakeholders all introduce themselves– Brief tutorials about areas represented in the

session (optional)– Brainstorming of ideas for the design– Walkthrough of the design and summary of

decisions made


Summary

In this session we looked at– Prototypes

• When and what sort to use

– Involving users in design• User Centred Design• Ethnography• Participative design

gary marsdenslide 1university of cape town human-computer interaction - 8 prototyping gary marsden (...

Documents