CSCD 487/587Human Computer Interface

Winter 2013

Lecture 3HCI and Interactive Design

Introduction

Last time …

–Defined “Interaction Design”• Designing interactive products to support

the way people communicate and interact in their everyday and working lives

• Looked at some Good and Bad designs

• Learned about history of user interfaces including people who created some early interface products

Good

BadUgly

Today's Overview

•What is Interaction Design?—Four basic activities

—Three key characteristics

•Some practical issues—Who are the users?—What are ‘needs’?—Where do alternatives come from?

—How do you choose among alternatives?—Some general guidelines

What is Interaction Design?

•It is a process—Goal-directed problem solving activity informed by

• Intended use,• Target domain,• Materials,• Cost, and feasibility• And, FORMOST - USERS

—Creative activity

Four basic activities

There are four basic activities in Interaction Design

1. Identifying needs and establishing requirements2. Developing alternative designs3. Building interactive versions of the designs4. Evaluating those designs

Three key characteristics

Three key characteristics permeate these four activities1. Focus on users early in design2. Identify, document and agree to specific

usability and user experience goals3. Iteration is inevitable. Designers never get it right first time !!!

Some practical issues

•Who are the users?

•What are their ‘needs’?

•Where do alternatives come from?

•How do you choose among alternatives?

Who are the users?

•Not as obvious as you think—Those who interact directly with the product—Those who manage direct users—Those who receive output from the product —Those who make the purchasing decision

User Categories

Three Categories of User Primary Frequent hands-on Secondary Occasional Tertiary Affected by its introduction, or will influence its purchase

Wider term: Stakeholders

Who are the stakeholders?

Check-out operators

CustomersManagers and owners

• Suppliers• Local shop owners

Grocery check-out System

Who are the users? • What are their capabilities? Humans vary in many dimensions!

• Some Examples— Size of hands may affect the size and positioning of input buttons— Motor abilities may affect the suitability of certain input and output devices — Height if designing a physical kiosk — Strength - a child’s toy requires little strength to operate, but greater strength tochange batteries

What are ‘needs’?•Do you agree with these statements?•Users rarely know what is possible•Users can’t tell you what they ‘need’ to help them achieve their goals

•Instead, look at existing tasks—Their context—What information do they require?—Who collaborates to achieve the task?—Why is the task achieved the way it is?

Where do alternatives come from?•Humans stick to what they know works

• But considering alternatives is important to ‘break out of the box’

•Designers are trained to consider alternatives• Software people generally are not

•How do you generate alternatives?—‘Flair and creativity’: Research & synthesis —Seek inspiration: Look at similar products or look at very different products

Or

Or

How do you choose among

alternatives?• Evaluation with users or with peers e.g. prototypes• Technical feasibility: Some not possible• Quality thresholds: Usability goals lead to usability CriteriaCan use these to help decide on correct design

Look at what exactly are Usability Goals ...

Usability Goals

• Look at usability goals to help determine best choice among possible designs

• What is usability in general?• Usability refers to ensuring that interactive products are easy to learn, effective to use, and enjoyable from the user's perspective.

Usability Goals

• Usability can be broken down into the following goals

• Effectiveness• Efficiency• Safety• Utility• Learnability• Memorability

Usability

Effectiveness Goodness of the product in meeting

its intended use Efficiency

Way product supports users in carrying out their tasks

Safety Protecting users from dangerous

conditions or undesirable conditions

Usability

Utility Refers to extent to which product

provides right kind of functionality so that users can do what they need to do

Example: Tax program that lets accountants do tax returns

Learnability How easy is a program to learn to use

Usability

Memorability How easy a program is to remember

how to use once learned These goals can transformed into

usability criteria Not all of these will be relevant to each

product!!

User Experience Goals

User experiences are somewhat objective and concerned with how a system feels to users

Two sides to describing user experiences

Desirable aspects and undesirable aspects

User Experience Goals

Desirable Program Aspects Satisfying, enjoyable, engaging,

pleasurable, exciting, entertaining, helpful, motivating, challenging, fun, provocative, surprising, rewarding

Undesirable Program Aspects Boring, frustrating, annoying,

childish, unpleasant, patronizing, cutesy, making you feel stupid

Principles of Design

Design Principles Used by designers to aid them in

designing the user experience Concerned with what users should

see and do when carrying out tasks Most common are:

Visibility, Feedback, Constraints, Consistency and Affordance

Principles of Design

Visibility The more visible functions are, the

more likely users will know what to do next

And, when functions are out of sight, more difficult to find them and know how to control them

Example: Sensor based lights

Principles of Design

Feedback Involves sending back information

about what action has been done And what has been accomplished Examples: Audio, visual, verbal, and

combinations

Principles of Design

Constraints Restricting kinds of user interaction

that can take place at a given moment Example: Greying out certain menu

choices Consistency

Design so interface has similar interactions for similar tasks

Example: Using mouse clicks for similar tasks

Principles of Design

Affordance Attribute of an object that allows

people to know how to use it Afford means to “give a clue” Example: Door handles, scissors,

hammer

Summary

Process of Interaction design is a four step process

Identifying needs and establishing requirements

Developing alternative designs Building interactive versions of the designs Evaluating those designs Usability Goals contribute to the process User experience goals also contribute to the

design process Common design principles should also be included

in and Interactive design process

The End

Reading

– Chapter 1 .. moving on to Chapter 2