ISE554

Human Computer Interaction Design

2.2 User Interface

Design

Sources of Information to Support DesignInteraction Designers require sources of information to help develop and integrate a design

Sources: • Scientific knowledge (cognitive psychology, organisational models etc.)• Established techniques(input/output via menus, forms, cursor control etc.)• Experience (design models, similar systems, interfaces etc)

But whilst knowledge, techniques and experience are invaluable they do not apply themselves to a particular problem

Hence the need for:

Guidelines: a valuable term which is over-used and often mis-used…

Important to distinguish between the different forms that guidelines take.

1. Definitions

Differentiate between:

1. HCI/ Interaction Design • Principles and Rules for the Design of an eLearning System

2. User Centred Design • Principles and Methods for the Design and Development of a Product, Artefact or

eLearning System

2. Definitions What is Design? (see Preece p 352)

“A creative activity- it involves bringing into being something new and useful that has not existed before.” (Jones, 1981)

It refers to:• 1) the process of developing a product, artefact or system..• 2) the models of the artefact developed during the process..

3. Design Product: The Lotus Bike

4. Creative Design: Process and Product• Paper “Artefacts and the Designer’s Process: Implications for Computer Support to Design”

- Date Artefacts Design Process Methods

- 1979 FIRST BIKES ADOPT ADAPT IMPROVE LEARNING CONVENTIONS

- 1980 FUNNY BIKES EXPLORATION BREAK RULES-- 1982 UNIVERSAL BIKE ANALYSIS FORMULATE PROBLEM

- 1985 MONOCOQUE 1 EMERGENCE EVOLVE NEW CONCEPT

- 1986 MONOCOQUE 2 ANALOGY MODIFY CONCEPT

- 1988 INTER BIKE REFINEMENT ADD FEATURES-- 1990 MONOCOQUE3 SYNTHESIS COMBINE FEATURES

- 1992 OLYMPIC BIKE COMPLETION APPLY MEASURES

- Figure 5 : Bicycle History Design Process and Knowledge Development

- See http://www.lindacandy.org.uk for the full history in words and images

5. System Centered Design

What can be built easily on this platform?

What can I create from the available tools?

What do I as a programmer find interesting to work on?

How can I ensure that the product /outcome matches the specification?

Is the program efficient?

6. User Centered System Design -1

The Design is based upon the user’s

• Capabilities and needs • Context • Work domain• Specific tasks

Golden rule of Interaction Design: “Know The User”

7. User Centered System Design - 2... is based on understanding the domain of work or play in which people are engaged and in which they interact with computers, and programming computers to facilitate human action. ...

From Denning and Dargan, p111 in Winograd, Ed., Bringing Design to Software, Addison Wesley

Denning and Dargan, 1996

Three assumptions

• The result of a good design is a satisfied customer

• The process of design is a collaboration between designers and customers. The design evolves and adapts to their changing concerns, and the process produces a specification as an important byproduct

• The customer and designer are in constant communication during the entire process

8. User-Centred Design Methods To achieve this, designers need to:• 1) understand user requirements in the context of domains, market..• 2) determine appropriate representations for exploring and communicating ideas

with users and to one another…

Methods • vary according to size, complexity and context of the design situation

1) Trial and Error Approaches• appropriate for simple designs, early exploratory concept generation, • limitations: cannot handle complex projects involving large teams…

2. Structured Approaches• appropriate for large scale engineering design work (aircraft, vehicles, computer

systems)• limitations: involving users more difficult and often given low priority, heavy

focus on detail not concept design-lack of creativity..

Computer tool: single application or machine Computer Environment : networked repertoire of toolsPerson : single individual working aloneTeam : groups of people with different skills expertiseworking as a group with common goalsContext: company or institutional framework with different constraints according to market or conditions

Computer tool Computer Environment

Team+Computer EnvironmentPerson

Team

Context

Object Activity Actors

Domain Model:Steering Column Connector

R1

R2

S1Generate

ClientFormulate Problem

Design Team

Analyse

EvaluateSelect

Design ManagerComputer tool/ designer

Specify

Feedback

MULTIK MODEL : DOMAIN MODEL REQUIREMENTS LAYER

Impose Constraint

Repeat Actors and Activities

Repeat Actors and Activities

R= Requirements