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HIT2316/6316 Usability

Intended Learning Outcomes

1. Describe the process and principles of User-Centred Design and explain the role ofUser-Centred Design in the software development process.

2. Discuss different methods of researching, analysing and documenting context of use(i.e., users, goals and tasks and environment).

3. Set and justify measurable usability requirements.4. Create a prototype user interface and discuss design decisions in relation to:

a. conceptual design,b. design guidelines,c. interface elements, and

d. psychological principles.5. Discuss different usability evaluation methods and critically evaluate user interfacedesigns using both inspection and empirical usability evaluation methods.

6. Describe and follow guidelines for the ethical treatment of research participants.

Generic Graduate Skills

1. Develop strategies to work collaboratively in a small team.2. Prepare effective written and oral reports.

Note: The aim of these notes is to provide you with a broad outline and context forthe material you are expected to learn in usability. These notes are not intended tobe your primary resource. You are strongly advised to read the text book.

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HIT2316/6316 Usability Faculty of Comunication and Information TechnologyKarola von Baggo Swinburne University of Technology

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Intended Learning Outcome 1

Describe the principles and process of User-Centred Design and explain the role of User-Centred Design in the software development process.

Assessment Criteria:

CriterionNot ready to

passPass

Credit-Distinction

HighDistinction

Knowledge andunderstanding

Student is unable toprovide a complete orlargely correct descriptionof the following concepts:

UCD principles,

UCD process,

ISO definition ofusability,

basic phases ofsoftware development,

software quality.

Student is unable toprovide an explanation ofthe relationship betweenany aspects of UCD andsoftware development.

Student is able to providecomplete and mostlycorrect description of thefollowing concepts:

UCD principles,

UCD process,

ISO definition ofusability,

basic phases ofsoftware development,

software quality.

Student is able to explainthe relationship betweenUCD and softwaredevelopment on at leastone dimension.

Explanation may not beentirely clear or wellexpressed.

In addition, student isable to illustrate UCDprinciples and processwithin a givensituation.

Student is able toexplain therelationship between

UCD process andprinciples.

Student is able to offera good explanation ofthe relationshipbetween UCD andsoftwaredevelopment.

Student is able toaddress therelationship on morethan one dimension.

In addition studentshows evidence of asophisticatedunderstanding of UCDand its contribution tosoftwaredevelopment.

Module 01 User-Centred Design:

Presentation 01.1: UsabilityPresentation 01.2: User-Centred DesignLecture Discussion Questions

Tutorial 01: Introduction

Assessment Method

Summative Assessment: Response to short essay question in final exam.Formative Assessment: Tutorial Exercises.

Required Reading:

Stone et al. Chapter 1Stone et al. Chapter 29

Extra Reading:

Bias, R. G. & C-M, Karat (2005). Justifying Cost-Justifying Usability. In Bias, R. G. andMayhew, D. J. Cost-justifying usability: An update for the internet age (2nd Ed).Morgan Kaufmann: San Franciso. (available as e-book from Library catalogue)

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Presentation 01.1 Usability

Introduction

To get your degree, most of you will do the equivalent of 24 units of

study. Each of these will help you bring technological solutions intoproblems people face in their lives. Usability is about trying to makesure that you bring the right solution to the people. The one that willmost improve their lives. No matter how elegant the code, or expensivethe technology, there is no point giving peoplea system that will make their life harder andcause them pain.

The purpose of this presentation is to startanswering the questions: What is usability?

Why does usability matter? What do you have to do to get a usable

product?First, I will start by introducing the idea thatpeople expect products to be easy to use andabout how usability benefits developers andthe community they serve. I will then talkabout how usability is defined and the way inwhich the definition gives us clues about how to get it. Finally, I will saya few words about the process of making usable products by talking

about the basic principles of User-Centred Design. The rest of thesemester will largely be focused on this last question.

People want products that are usable.

What People Care About

In the past computers were programmed by the people who usedthem. Or by people very like them. It was part of the fun of it,tinkering around trying to get the code to do what you wanted it to do.Its not like that today. Today, everyone is touched by technology,whether they like it or not. You dont even have to own a computer to

be affected by the dreams of system designers and programmers (justthink about the use of technology in the medical, banking andgovernment sectors not to mention train ticket systems, microwavesand air-conditioners).Unfortunately, the majority of people today dont want to think aboutthe code, or about the way the system is put together. Its not becausethey are dumb, rather its because all they care about is doing whatthey want to do. Whether thats formatting a business report, making atelephone call, arranging photos, playing a game or listening to music.

Anything that gets in the way of what they want to do is an annoyance

and a reason not to use a product.

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Developers need to make products that are usable.

Product Success

If people dont like a product, and they have a choice, then theywont use it, or wont buy something from you again, or wontrecommend it to their friends. If people dont have a choice becausethey have to use it at work, then they may perform poorly at their job,or even decide not to come to work (i.e., take sick days). Indeed, somemeasures of usability in industry environments count number of sickdays as a measure of success for a new system.

Usability is not something that can be added at the end of

development.

Usability is Not the Icing on the Cake

No developer intentionally sets out to build a bad product. However,sometimes usability is perceived as something that can be added atthe end. A bit like the icing on the cake, a finishing touch to make itlook good. Aesthetics (how good something looks) certainly contributesto the user experience. However, no amount of icing is going to turn apumpkin and zucchini cake into a chocolate cake!

Usability has the greatest impact in the early stages of development.

Usability

The concern of usability is more than the surface appeal of a product.

It is about allowing users to work (or play) in a way that meets theirneeds. It goes to the underlying structure of the interaction, thesequence in which people do tasks and the way in which information isorganised. Sometimes early decisions about system architecture canconstrain the possible user interactions with the product. Therefore itis important to consider usability early in the process.

Make usability a key part of product development.

Learn about Usability

Applied with intelligence and care, the things you learn in this unit will

help you develop products that will meet the needs of your users. Myhope is that at the end of this unit you will build on your skills andintuition to create great products.

Usability is the extent to which a product can be...

The ISO 9241-11 Definition of Usability

ISO is the International Organization for Standardization which specifiesgood practice in a range of disciplines. They have a section on User-Centred Design and Usability. They define usability as:

The extent to which a product can be used byspecified users to achieve specified goals with

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effectiveness, efficiency and satisfaction in a specifiedcontext of use.

The definition, as does most of the ISO standards, comes from abackground of business and military products for which there hastraditionally been a strong focus on time and motion. The definition

does not necessarily capture the full meaning of what it means for aproduct to be usable. However, it is useful as a starting point andprovides an insight into the concerns of usability.

...used by specified users to achieve specified goals...

Users Achieving Goals

The ISO definition of usability recognises that usability is dependenton the context of the interaction. Usable products are designed forparticular users to carry out particular tasks in particularenvironments. A common trap for developers is that they build a

product that works, but only for a particular type of user (usually onelike themselves). Problems then arise when the intended (real) userstry to use the product. So, if you design for the wrong user (i.e.,yourself, or some imagined user you have dreamt up while sitting atyour computer), your product will not be successful with the realusers. One thing that should be clear from this is, that to design ausable product, you must have an extremely good idea of who yourusers are and what they are trying to achieve.

...with effectiveness, efficiency and satisfaction...

Usability MeasuresISO refines the concept of usability by narrowing it down to threedimensions, effectiveness, efficiency and satisfaction.Effectiveness: the accuracy and completeness with which specifiedusers can achieve specified goals in a specified environment;Efficiency: the resources expended in relation to the accurac andcompleteness of the goals achieved; Satisfaction: the comfort andacceptability of the work system to its users and the people affectedby its use Stone et al (2005)

...in a specified context of use.

Context of Use

A lot of technology use occurs in air-conditioned comfort. Sometechnology needs to work well in other types of circumstances suchas; on the road, in extreme temperatures, with constant interruptions,or in dirty environments. A product designed for one environment willobviously not work as well in a different environment. So, it is importantthat you know what kind of environment your product will be used in.Note: ISO implies that 'environment = context of use' in this definition,but later appears to assume that 'users + tasks and goals +environment = context of use'. The latter description will be used inthis unit except in regard to the definition of usability.

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Usability is good value for money.

Return on Investment

Implementing a User-Centred Design process does not come forfree. Time and money need to be spent on planning, implementingand analysing the results of UCD activities. Building a case to

persuade your team or managers to spend resources on UCDactivities is an important part of the process. There are a number ofpoints at which usability can contribute to the bottom line.It will help if we have a quick look at the type of activities typicallyundertaken in a software development project before we start thisdiscussion. These are:Requirements definition (establish goals of users and any constraints)System Software Design (developing the system architecture)Implementation and unit testing (developing components)Integration and system testing (putting components together)

Operation and maintenance (system installationand use)

Usability prevents costly late design changes.

Late Design Changes

If you look across the development life cycle, inthe early stages of requirements gathering, thereare a multitude of potential design solutions tobe considered. As development progresses anddecisions are made about the direction of theproduct, the possible number of designalternatives decrease, until at the end you havethat one design that is finally deployed. Animplication of this is that early on in the process you may have a lot offreedom to decide what gets built. But as you start building things yourability to change decreases because you might waste the work alreadydone.So while a design change may cost $1 to fix in the early stages ofrequirements gathering, it might cost $100 to change later in the

development process. Starting requirements with an early focus on theusers can help pick up problems before design problems progress intothe development or deployment phase and hence save money.

Usability influences sales and customer support calls.

Sales and Support

Good usability can affect the desirability of the product. As peoplebecome more familiar with a product they can develop strongerpreferences for ease of use over functionality that they never use.When trying to sell stuff on the web, easy to use is particularly

important. A competitors website is only a back button away on theusers Google search list. Support calls is sometimes overlooked by

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the development team because it generally not something that goesinto their budget. However, a large volume of support calls can be abig drain on a company and even small improvements in usability canbe beneficial if they reduce calls to the help line.

Usability influences productivity, errors and training.

Business Sense

Improvements in the usability of a product can increase theproductivity of the users. Imagine if you reduced the processing timeof a transaction by a few seconds by improving the usability of theproduct. You could eliminate the need to open a new window, orreduce the number of data entry errors by reformatting the entry field.In a large system this may equate to thousands of dollars of staff time.Even in small systems the savings gains can be considerable.

Another source of savings is in training time. Often teams justify poor

usability by putting their faith in training (I.e., we dont have to worryabout that, training will take care of it). However, training can be veryexpensive, not just because you have to employ trainers. The workersalso have to take time off for the training.

Usability is the product of User-Centred Design.

User-Centred Design

So far I have talked about what usability is. Now I would like to touchon how you get a usable product. Designing for usability issometimes thought of as simply using common sense. Unfortunately,

common sense doesnt seem all that common. It is also difficult toapply if you are not fully informed about the users, their goals and thecontext they are working in. User-Centred Design (UCD) is a processthat you can use to help insure that your final product can be used asintended. Later, I will talk some more about the process of UCD, forthe moment I would like to address the three key principles of UCD;early focus on users, measurement and iteration.

The first principle is early focus on users and tasks.

Early Focus on Users

Sometimes, when usability is factored into a project time line, it istacked on to the end with an item such as Usability Test. Althoughdoing a usability test at the end can be useful in terms of identifyinghow usable your final product is, it doesnt help you actually design ausable product in the first place. To do that you have to start with theconcerns of the user at the very beginning of the project. As we havealready discussed, you need to identify who the users are, what theyare like and what they are trying to achieve. If you dont do this you runthe risk of your product being misdirected and not satisfying the peoplewho pay your bills.

The second principle is measurement.

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Measurement

Imagine you set yourself the goal of your product being easy to use.How will you tell whether you have met this goal? A key aspect ofany engineering process is to have measures of success so you knowyou have built the product to specifications. The same is true forusability. Unless you can measure your usability outcomes you canttell if you have been successful or not. Example measures foreffectiveness might be the number of tasks successfully completed,for efficiency, the time taken to do a task and for satisfaction, it couldbe a score on a satisfaction questionnaire. The appropriate measurewill depend on the product under development.

The third principle is iterative design.

Iteration

I have not failed. I've just found 10,000 ways that won't work.

Thomas Edison (inventor of the light bulb amongst other things). It isunlikely that your first idea to solve a design problem will be the best.Unfortunately, good design cant be engineered according to a fixedset of rules (however, we will talk about design guidelines later in thesemester). By its nature, design involves a certain amount ofexperimentation with alternative solutions to find the best solution.Iteration is the process of creating a design, testing it, revising itaccording to the results of the testing, and testing it again. Prototypingis a key component of this process and we will also be learning moreabout this in a couple of weeks.

Can you make usability a feature of your work?

Use the opportunity you have in this unit to learn how to createproducts that help people in their daily lives rather than make it amisery for them. Usability will also come in handy during the rest ofyour degree. Most 'programming' units don't include 'usability' as acriteria in their marking schemes. However, most of the project unitsdo. These are units where you develop a piece of software for a realclient. Depending on the product you may need to take usabilityquite seriously. In fact many conveners require you to do usability

testing.Usability is not the icing on the cake.

Learn how to make usability part of your work.

Usability connects people and technology.

You can't prevent people from putting beans in their noses. But you

shouldn't stuff beans in their noses." - Stan Schwartz

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Presentation 01.2 User-Centred Design

The purpose of this presentation is to provide you with an overviewof User-Centred Design (UCD) activities. As the unit progresses wewill step through each of the phases of the UCD process in more

detail.Before we begin I will start by outlining the issue of Software Qualityand the

Software should be good.

Most developers set out to make good software.

Software developers are responsible for software quality.

ISO 8402 Defines quality as: The totality of characteristics of an entitythat bear on its ability to satisfy stated and implied needs.

The term characteristics in this definition is very broad. It covers a lotof things from how nice the code is to whether the user is happy withthe colour scheme. Luckily there is another ISO standard thatbreaks this down a bit further...

Software quality is comprised of six attributes.

Software QualityISO 9126 identifies six aspects of software quality:

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Attribute Description

functionality the capability of the software to providefunctions which meet stated and impliedneeds when the software is used underspecified conditions.

reliability the capability of the software to maintain itslevel of performance when used underspecified conditions.

usability the capability of the software to beunderstood, learned, used and liked by theuser, when used under specified conditions.

efficiency the capability of the software to provide the

required performance, relative to theamount of resources used, under statedconditions.

maintainability the capability of the software to bemodified. Modifications mayinclude corrections, improvements oradaptation of the software to changes inenvironment, and in requirements andfunctional specifications.

portability the capability of software to be transferredfrom one environment toanother.

You will notice that usability is one of the six.

Usability is an attribute of software quality.

In an IT degree you will have units devoted to different aspects ofmaking good software. In this unit of course we will be concernedwith the usability aspect of software quality. That is, strategies for

optimising the usability of the products you make.

User-Centred Design provides a method for obtaining usability.

User-Centred DesignSoftware Development Life Cycles (SDLC) are management toolsthat help the development team track and plan their progressthrough the term of the project. You need a life cycle model to planwhat you do, it provides you with a guide as to what kinds of thingshave to get done to get the software built.User-Centred Design (UCD) is a SDLC model that has grown out ofconcern for the user. The question posed by a UCD approach is notHow can we use this technology But How can we best support the

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user. Sometimes the answer might not be in the technology. I will nowdiscuss the five parts of the UCD process.

Include User-Centred Design activities in your process plan.

Planning

To include User-Centred Design activities in your life cycle, you needto plan for them.Management

Get management buy-in on a User-Centred approach. Differentorganisations have different levels of maturity when it comes toemploying a User-Centred approach. Some may already be on theway to a User-Centred focus. Others may not yet understand how theprocess might benefit the organisation and may resist the notion ofspending time and money on user-centred design activities. As anadvocate of UCD you need to be prepared to argue the case for UCD.

Plan to include User-Centred tasks in your process.Schedule

If you dont put UCD activities in the to-do list, they wont get done.When developing a time line you need to block in time for UCD.Courage & Baxter have example timelines of how long it takes to set upvarious UCD activities. For some activities it may take a number ofweeks to get everything prepared.Money

Budget for User-Centred Design activities.UCD activities do require resources. There may be equipment to

purchase, or people with specialist skills may need to be brought in not

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to mention the person hours involved in setting up, gathering andanalysing data.

This is an important stage of the UCD process. However, we do nothave time to go into any more depth on this topic. Some issues arefollowed up in Chapter 29 of Stone et al. You may also do other unitsin your degree which look at management issues in more detail.

Research the context of use to understand the problem domain.

User Characteristics

Gather data on user characteristics. Gathering information about yourusers is the first step in understanding who your users are. Importantcharacteristics may be previous experience with technology, attitudetowards computers and motivation to master the product. We will talkmore about this next week.Goals and Tasks

Gather data on user goals, tasks and activities.As will be come evident next week, user goals are a key motivatingfactor in understanding what the product has to do. One importantpoint to note is that goals and tasks are different. For example, for aparamedic, the task may be to find the quickest route to his patientslocation, but his goal is to save the patients life. The goal doesntchange, but the way he achieves it might.Environment

Gather data on the environment The system environment can beanalysed in terms of a number of different dimensions such as the

physical, social and technical environment.Specify usability requirements to ensure quality of use.

Effectiveness: Users can achieve their goals completely andaccurately.Efficiency: Users can achieve their goals with an acceptable amountof effort. Satisfaction: Users are free from discomfort and have apositive attitude towards the product.

Prototype alternative design solutions.

Refine RequirementsRefine requirements by showing prototypes to users and clients.Sometimes it is difficult for users to get an idea of what you areproposing as the solution for their problem. Showing them your ideaswith prototypes is an effective way of communicating yourunderstanding of their problem.Iterative Design

To get one good idea, get many ideas. Explore designs quickly withlow and mid-fidelity prototyping. Remember one of the key principlesof UCD was iterative design (i.e., design, test, redesign)? Doing this

with real code makes the process very resource intensive. You canreduce the resources required by using low fidelity prototyping. The

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ability to do rapid prototyping will be one of the most valuable skills youto take away from this unit.

Evaluate whether your design meets your usability requirements.

Evaluation

Test early, test often. You dont have to wait until you have a fullyfunctioning bit of code to do testing. Testing can begin at any stage,even on paper based sketches. This process is known as formativetesting.Usability Evaluation Methods

Choose a technique to suit your time, budget and prototype. There arearrange of different techniques you can use do get an evaluation onyour design. Which technique you choose will depend on time, moneyand how far along your prototype is along the development path.(Almost) any evaluation is better than no evaluation.

I would like to say that any evaluation will help you improve yourdesigns. However, that is not quite true. Making important decisionsbased on poorly conceived evaluations may ultimately do more harmthan good. Indeed I have known people to loose faith in the processquite completely because of this kind of thing. Thus, you do need tounderstand the limitations of the different kinds of methods.Evaluate whether your design meets your usability requirements.

Can you implement User-Centred Design to improve your product?

Responsible software developers deliver quality software.

Usability is one of six software quality attributes.

Implement User-Centred Design to maximise usability.

"... this is so simple a five year old child could understand it. "Quick,

run out and bring me a five year old child." - Groucho Marx

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HIT2316-6316 Module 1