SE365 · LECTURE 5 · SLIDE BREAKDOWN

Designers never get it right
the first time.

Interaction design is a process: discovering requirements, designing to fulfil them, producing prototypes and evaluating them - focused on users and their goals, and involving trade-offs to balance conflicting requirements. Generating alternatives and choosing between them is the key skill.

4 design approachesUser involvement3 UCD principles4 basic activitiesStakeholder categoriesA/B testing

LEARNING OUTCOMES

Explain the advantages of involving users in development.
Explain the main principles of a user-centered approach.
Present a simple lifecycle model of interaction design.
Identify users and stakeholders and explain what 'needs' means.
Explain where alternatives come from and how to choose among them.

01 - INTERACTION DESIGN AS A PROCESS

Four approaches, one process

Interaction design is a process focused on discovering requirements, designing to fulfil them, producing prototypes and evaluating them; focused on users and their goals; and involving trade-offs to balance conflicting requirements.

The four approaches	What drives the design
User-centered design	The user is the primary source; the designer studies and involves them.
Activity-centered design	The activity being carried out, rather than any individual user.
Systems design	The system and its context as a whole.
Genius design	The designer's own creative judgement and expertise.

Before designing anything you must explore the problem space: what is the current user experience, why is a change needed, and how will this change improve the situation? Articulating the problem space is a team effort - it means exploring different perspectives and avoiding incorrect assumptions and unsupported claims.

MEMORY HOOK

Four approaches, four sources of authority: the user, the activity, the system, the designer. Only the last one is not a source of evidence - which is why the course teaches the first.

02 - INVOLVING USERS

Degrees of user involvement

There is no single right level of user involvement - each option trades input quality against the user's continued representativeness.

User as team member	Benefit	Cost
Full time	Constant input.	They lose touch with the users they represent.
Part time	Keeps one foot in the user community.	Patchy input, and very stressful.
Short term	Fresh perspective.	Inconsistent across the project's life.
Long term	Consistent input.	They lose touch with users.

Face-to-face group or individual activities.
Online contributions from thousands of users: Online Feedback Exchange (OFE) systems, crowdsourcing design ideas, and citizen science.
User involvement after product release - the process does not stop at launch.

THE CENTRAL TENSION

Notice that full time and long term have the same drawback: the more embedded a user representative becomes in the design team, the less they resemble the users they were recruited to represent. That is why user involvement must be refreshed, not just secured once.

03 - USER-CENTERED DESIGN

The three principles

A user-centered approach rests on exactly three principles, and the exam expects all three.

Early focus on users and tasksDirectly studying cognitive, behavioural, anthropomorphic and attitudinal characteristics.
Empirical measurementUsers' reactions and performance to scenarios, manuals, simulations and prototypes are observed, recorded and analysed.
Iterative designWhen problems are found in user testing, fix them and carry out more tests.

MEMORY HOOK

Study them early, measure them empirically, then do it again. Early focus → empirical measurement → iteration. Each principle feeds the next, and the third feeds back into the first.

04 - THE FOUR BASIC ACTIVITIES

Requirements, alternatives, prototypes, evaluation

These are the same four activities named in Lecture 1, now with their internal detail. Three key characteristics permeate all four.

1. Discovering requirements

To design, you must know your target users and what kind of support an interactive product could usefully provide. This is fundamental to the user-centered approach, and these needs are understood through data gathering and analysis.

2. Designing alternatives

The core activity: suggesting ideas for meeting the requirements. It breaks into two sub-activities. (a) Conceptual design - producing the conceptual model, describing what people can do with the product and what concepts are needed to understand how to interact with it. (b) Physical design - the details: colours, sounds, images, menu design, icon design.

3. Prototyping

The most sensible way for users to evaluate a design is to interact with it. Paper-based prototypes are very quick and cheap to build and very effective at identifying problems in the early stages. Through role-playing, users get a real sense of what it will be like to interact with the product.

4. Evaluating

The process of determining the usability and acceptability of the product or design - testing to make sure the final product is fit-for-purpose.

THE THREE KEY CHARACTERISTICS

1. Focus on users early in the design and evaluation of the artefact. 2. Identify, document and agree specific usability and user experience goals. 3. Iteration is inevitable - designers never get it right the first time.

Alternative lifecycle model	Source	Character
Simple interaction design lifecycle	Sharp, Preece & Rogers	The four activities in an iterative loop.
Google Design Sprints	Knapp et al. (2016)	A compressed, time-boxed run through the same logic.
Research in the Wild	Rogers & Marshall (2017)	A framework for studying technology in natural settings.

05 - WHO ARE THE USERS?

Users, stakeholders, and the three categories

"Who are the users?" is not as obvious as it sounds. Sha Zhao et al. (2016) identified 382 distinct types of users for smartphone apps.

Many products are intended for large sections of the population, so the user is "everybody". More targeted products are associated with specific roles.
Stakeholders are a larger group than direct users. Identifying them helps identify which groups to include in interaction design activities.
Stakeholders include: 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; and those who use competitors' products.

Eason's (1987) three categories	Definition
Primary	Frequent, hands-on users.
Secondary	Occasional users, or people who use it via someone else.
Tertiary	People affected by its introduction, or who will influence its purchase.

MEMORY HOOK

Primary touches it, secondary occasionally touches it, tertiary is touched by it. The tertiary category is the one people forget - and it includes the person signing the cheque.

06 - NEEDS AND ALTERNATIVES

What 'needs' means, and where alternatives come from

Users rarely know what is possible, so you cannot simply ask them to state their requirements.

Explore the problem spaceUnderstand the situation before proposing solutions.
Investigate who the users areIdentify roles, categories and stakeholders.
Investigate user activitiesSee what can be improved in how things are done now.
Try out ideas with potential usersTest rather than ask.

THE KEY SENTENCE

Focus on people's goals, and on usability and user experience goals, rather than expecting stakeholders to articulate requirements. Users are experts in their problems, not in your solutions.

Humans tend to stick with something that works, so considering alternatives is what identifies better designs. The lecture lists where they come from:

Flair and creativity - research and synthesis.
Cross-fertilisation of ideas from different perspectives.
Users can generate different designs.
Product evolution based on changing use.
Seeking inspiration from similar products and domains, or from different products and domains.
All of it balanced against constraints and trade-offs.

07 - CHOOSING BETWEEN ALTERNATIVES

Externally visible, measurable behaviour

Interaction design focuses on externally visible and measurable behaviour, which is why the choice between alternatives is made with prototypes rather than documents.

Technical feasibility

Some ideas are simply not buildable within the project's technology, budget or time.

Evaluation with users or peers

Use prototypes, not static documentation, because behaviour is the thing being judged and documentation cannot behave.

A/B testing

An online method for informing the choice between alternatives. It is nontrivial to set appropriate metrics and to choose the user group sets.

Quality thresholds

Different stakeholder groups have different quality thresholds. Usability and user experience goals lead to the relevant criteria.

MEMORY HOOK

Why prototypes and not documents? Because behaviour is key, and a document does not behave. That one clause answers most questions in this section.

MISTAKES STUDENTS USUALLY MAKE

Mistakes students usually make

Each claim below is the wrong answer; the line beneath it is the correction, in the wording this course marks against.

Giving only two user-centred design principles.

There are three: early focus on users and tasks, empirical measurement, and iterative design. Dropping empirical measurement is the most common omission.

Confusing conceptual design with physical design.

Both are sub-activities of designing alternatives. Conceptual design produces the conceptual model - what people can do and what concepts they need. Physical design covers colours, sounds, images, menus and icons.

"Ask the users what they need."

Users rarely know what is possible. Explore the problem space, investigate users and their activities, and try out ideas with them - focusing on goals rather than stated requirements.

Treating stakeholders as a synonym for users.

Stakeholders are a larger group: managers of direct users, recipients of the output, purchasers, and users of competitors' products. Eason's categories are primary, secondary and tertiary.

Assuming full-time user involvement is best.

Full-time involvement gives constant input but the representative loses touch with users - the same drawback as long-term involvement.

Choosing between alternatives using specifications.

Interaction design focuses on externally visible and measurable behaviour, so the choice is made with prototypes, not static documentation.

CHEAT SHEET

Shortest correct answers

The night-before table: every term in this lecture with the smallest answer that still earns the mark.

Concept	Shortest correct answer
Four design approaches	User-centered, activity-centered, systems design, genius design.
UCD principles (3)	Early focus on users and tasks; empirical measurement; iterative design.
Four basic activities	Discovering requirements, designing alternatives, prototyping, evaluating.
Designing alternatives	Splits into conceptual design (the model) and physical design (colours, sounds, images, menus, icons).
Three key characteristics	Early focus on users; documented usability and UX goals; iteration is inevitable.
Eason's user categories	Primary (frequent hands-on), secondary (occasional or via someone else), tertiary (affected by it or influencing purchase).
Degrees of involvement	Full time, part time, short term, long term; plus OFE systems, crowdsourcing, citizen science, and post-release involvement.
Needs	Users rarely know what is possible; explore the problem space, investigate users and activities, try ideas out, focus on goals.
Sources of alternatives	Flair and creativity, cross-fertilisation, users, product evolution, inspiration from similar and different domains.
Choosing alternatives	Technical feasibility, evaluation with users or peers using prototypes, A/B testing, quality thresholds.
A/B testing	An online method for choosing between alternatives; setting metrics and user groups is nontrivial.
Paper prototypes	Quick, cheap and very effective at identifying problems in early design.

APPLY IT

Exam-style application

Write your own answer first, then open the model answer. These are the longer-form questions this material generates.

Your client says "just ask our customers what features they want, then build those." Explain why this is not what the course means by establishing needs.

Users rarely know what is possible, so asking them to name features returns variations on what already exists rather than what would actually help. The course's approach is to explore the problem space (what is the current experience, why is a change needed, how would it improve things), investigate who the users are including secondary and tertiary stakeholders, investigate user activities to see what can be improved in the way things are currently done, and try out ideas with potential users. Throughout, the focus is on people's goals and on agreed usability and UX goals, rather than on stakeholders articulating requirements. Humans stick with what works, so alternatives have to be deliberately generated rather than requested.

Identify primary, secondary and tertiary users for a university course-registration system, and say which you would recruit for testing.

Primary: students registering for courses - frequent hands-on use. Secondary: academic advisors who occasionally register a student on their behalf, and registry staff who correct entries. Tertiary: the deans who approve the purchase, the timetabling office affected by the resulting enrolment data, and IT support who inherit the maintenance. For testing, recruit primary users for task performance because they generate the volume of use, but include secondary users because their tasks differ structurally rather than in frequency, and consult tertiary stakeholders on requirements and quality thresholds - they set constraints even though they never touch the interface.

Your team is split between two navigation designs. Describe how you would choose, using this lecture's criteria.

First check technical feasibility - can both be built within the project's constraints? Then build prototypes rather than documents, because interaction design focuses on externally visible and measurable behaviour and only a prototype behaves; paper prototypes are quick, cheap and effective at this stage. Evaluate with users or peers against the specific usability and UX goals agreed at the start, since those goals supply the criteria. If the product is live and the change is small, run an A/B test, remembering that setting appropriate metrics and choosing the user group sets is nontrivial. Finally check the result against the quality thresholds of each stakeholder group, which differ - what satisfies a casual user may fail an expert or a purchaser.

POP QUIZ

Check yourself

6 questions. Every option is explained after submitting, including why the wrong ones are wrong.