User-Centered Design (UCD) CS 352 Usability Engineering Summer 2010

Announcements Quiz tomorrow (Ch 1, 2’s readings, up to today’s lectures) Readings: – Finish reading Ch 2. – ('07 version)Read 9.2. ('02 version) Read 9.2 and 9.3. Just skim b’c we will cover them in detail in today’s lecture. Project proposal part 1, 2 due next Tue, part 3 due next Thu. 2

Review of this week’s lectures on design The PRICPE process Pre-dispositions Research Insights Concept Prototype Evaluation Where does the user come in? Today and next few days’ lectures 3

User-Centered Design Principles [ch. 9] Early and continual focus on users and tasks Empirical measurement Iterative design 4

User-Centered Design Principles [ch. 9]  Early and continual focus on users and tasks Empirical measurement Iterative design 5

Early focus on users and tasks 1.Users’ tasks and goals are the driving force behind the development. “Where can we deploy this new technology?” vs. “What technologies are available to provide support for users’ goals?” 2.Users’ behavior and context of use are studied and the system is designed to support them. – Highlights preferences, priorities, implicit intentions – E.g., (Fahmy & Spencer) Families keep shopping lists  a reusable virtual shopping list – E.g., (Jeen, Moon & Rob) People are on-the-go  Google Map – E.g., (Greg & Scott) Touch screen in the kitchen  large buttons 3.Users’ characteristics are captured and designed for. – E.g., (Brian & Chris) Seniors are risk-aware and don’t want to send their credit card numbers over the internet  pay upon arrival 6

Early focus on users and tasks (cont.) 4.Users are consulted throughout development from earliest phases to the latest, and their input is seriously taken into account. 5.All design decisions are taken within the context of the users, their work, and their environment. 7 Keep your users in mind at all times!!

User-Centered Design Principles [ch. 9] Early and continual focus on users and tasks  Empirical measurement Iterative design 8

Empirical measurement Empirical - derived from experiment and observation (wordnetweb.princeton.edu) Empirical measurement for usability and user experience goals – Allows designers to evaluate their designs – Help designers choose between alternatives 9

User-Centered Design Principles [ch. 9] Early and continual focus on users and tasks Empirical measurement  Iterative design 10

Iterative design 11

Some practical issues Who are the users? What do we mean by needs? How do you generate alternative designs? How do you choose among alternatives? 12

Some practical issues  Who are the users? What do we mean by needs? How do you generate alternative designs? How do you choose among alternatives? 13

Who are the users? People who – directly use the system to achieve a task – manage the direct users – make the purchasing decision Primary (frequent hands-on users) Secondary (occasional users) Tertiary (those affected by the intro of system or who will influence its purchase) Stakeholders – “people or organizations who will be affected by the system and who have a direct or indirect influence ” [Kotonya & Sommerville ‘98] 14

Activity Who do you think are the stakeholders for the check-out system of a large supermarket? Possible answers: – Check-out operators – Customers (right amount, correct receipt, quick & efficient) – Supermarket managers, supermarket owners (want assistants happy, customers satisfied, don’t want to lose money) – Others, e.g., warehouse staff, suppliers, … 15

Some practical issues Who are the users?  What do we mean by needs? How do you generate alternative designs? How do you choose among alternatives? 16

What do we mean by “needs”? Designer: “What do you need?” User:“I need blah, blah, blah…” Designer:“Ok, let’s do that!” Is this always the case? No, often times, user do NOT know what they want!!! 17

Users do not always know what they need… We approach this by understanding … – The characteristics and capabilities of the user – What they are trying to achieve – How they achieve it currently – Whether they would achieve their goals more effectively 18

Users do not always know what they need… We approach this by understanding …  The characteristics and capabilities of the user – What they are trying to achieve – How they achieve it currently – Whether they would achieve their goals more effectively 19

Users do not always know what they need… We approach this by understanding … – The characteristics and capabilities of the user 20 Physical e.g., size of hands decides size of keys of a keyboard e.g., motor disabilities  eye tracking input

Users do not always know what they need… We approach this by understanding … – The characteristics and capabilities of the user 21 Cognitive  memory, e.g., the magical number of 7+2 perception problem-solving learning attention …

Users do not always know what they need… We approach this by understanding … – The characteristics and capabilities of the user 22 Cognitive memory, e.g., the magical number of 7+2  perception problem-solving learning attention … Pictures on visual perceptions from design.org/encyclopedia/gestalt_principles_of_form_perception.html Law of Proximity

Users do not always know what they need… We approach this by understanding … – The characteristics and capabilities of the user – What they are trying to achieve – How they achieve it currently – Whether they would achieve their goals more effectively 23 Case Study: StratCell

StratCell [Grigoreanu et al. ‘10] A spreadsheet system with debugging aid Target users: spreadsheet users 24

So what do we do? We approach it by understanding … – The characteristics and capabilities of the user  What they are trying to achieve – How they achieve it currently – Whether they would achieve their goals more effectively 25 Case Study: StratCell

What users are trying to achieve? Reliable spreadsheets “Barclays Capital agreed to purchase some of Lehman’s assets but, due to a spreadsheet error resulting from hidden dependencies, the company purchased assets for millions of dollars more than they had intended [13].” [Grigoreanu et al. ‘10] Task: – finding and fixing errors in spreadsheets 26

Users do not always know what they need… We approach this by understanding … – The characteristics and capabilities of the user – What they are trying to achieve  How they achieve it currently – Whether they would achieve their goals more effectively 27 Case Study: StratCell

How users currently achieve it? User studies!!! – Lab study, task to debug spreadsheets – Interaction logs, self-reported questionnaire Findings: – 8 debugging strategies including Testing, Code Inspection, Dataflow, To-do Listing, etc. 28 P Research ICPE UCD’s “early & continual focus on the user” principle P Research ICPE UCD’s “early & continual focus on the user” principle PR Insights CPE

Users do not always know what they need… We approach this by understanding … – The characteristics and capabilities of the user – What they are trying to achieve – How they achieve it currently  Whether they would achieve their goals more effectively 29

Help users achieve their goals more effectively 30 PRICP Evaluate UCD’s “empirical measurement” principle PRICP Evaluate UCD’s “empirical measurement” principle PR Insights Concept Prototype E UCD’s “iterate” principle PR Insights Concept Prototype E UCD’s “iterate” principle

Take-away Users did not say “I need a tool to help me debug my spreadsheets”. It is the designer’s job to help the users figure out what they really need! 31

Some practical issues Who are the users? What do we mean by needs?  How do you generate alternative designs? How do you choose among alternatives? 32

How do you generate alternative designs? One pragmatic answer: – “…alternatives come from looking at other similar designs, and the process of inspiration and creativity can be enhanced by prompting a designer’s own experience and by looking at others’ ideas and solutions.” [text p435 ‘07 ver.] One caveat: – May become overly influenced by others’ ideas 33

Activity Consider yesterday’s online grocery system you designed. 1.Reflecting on the process again, what do you think inspired your outline design? 2.See if you can identify any elements within it that you believe are truly innovative. 34

Some practical issues Who are the users? What do we mean by needs? How do you generate alternative designs?  How do you choose among alternatives? 35

How do you choose among alternatives? Possible answers: – External (users can see) vs. internal (users cannot see) features In usability engineering, the driving force behind the design is the way the users interact with the product  External! This is not to say internal features are unimportant. – Let users and stakeholders interact w/ your designs  requires prototyping (more coming later in this course) 36

Announcement Quiz tomorrow Reading: ('07 version)Read 9.2. ('02 version) Read 9.2 and 9.3. Just skim because we have already covered them in detail in today’s lecture. Project proposal due next Tue. 37

Announcements Quiz tomorrow (Ch 1, 2’s readings, up to today’s lectures) Readings: – Finish reading Ch 2. – ('07 version)Read 9.2. ('02 version) Read 9.2 and 9.3. Just skim b’c we will cover them in detail in today’s lecture. Project proposal part 1, 2 due next Tue, part 3 due next Thu. 38