usability 101: the principles of usability engineering tuesday, august 6, 2002
TRANSCRIPT
Usability 101: The Principles of Usability
Engineering
Tuesday, August 6, 2002
Agenda
• Discuss the value of user-centered design• Describe the user-centered design and usability
engineering lifecycle• Discuss the usability testing process
Who We Are
• Communication Technologies Branch (CTB) – National Cancer Institute’s Office of Communications
• CTB Mission– To analyze, design, evaluate, and test communications
technology systems, (Web sites, software, mobile technologies) to make them more usable, useful, and accessible
Why We Do It
• Failure of Web sites
– Users find information they’re seeking on Web sites only 42% of the time (Spool study of 15 large commercial sites)
– Only 51% of sites complied with simple Web usability principles (Forrester study of 20 major sites)
– Sixty-two percent of web shoppers gave up looking for an item (Zona study)
Traditional Development Process
How We Do It
• Usability Engineering– An evidence-based methodology that involves end users
in the design, testing, and evaluation processes to produce information systems that are measurably easier to use, learn, and remember
– Process involves:• Data collection about users’ needs/wants/behavior
• Prototype development
• Usability testing
• Iterative design/usability testing
How We Do It
• Research-Based Approach
– This approach applies the latest design and testing research to the development of communication technology systems, products, and services
– Modeled after the scientific community’s movement toward “evidence-based” medicine/science
– Involves a review of the research data related to Web design, usability, accessibility, and more
– Identifies gaps in the research – many areas have yet to be studied
Why We Do It
• Usability Engineering Works– It’s user-centric (not developer-centric)– It’s based on data, not opinions– It’s testable and verifiable– It’s performance-driven– Saves money and time
• Research-based Information Design Works– Removes much of the controversy in opinion– Performance oriented – measurably better/faster/etc.– Takes the guesswork out – allows you to focus on what
you don’t know – to solve problems
Usability Engineering Process
• Steps in the process– Planning– Gathering user data– Analyzing data– Translating data into design– Designing initial prototypes– Testing prototypes– Refining prototypes, retesting, retesting…
Planning
• Planning Steps– Define purpose / vision for the site– Develop measurable business objectives & user goals– Define primary / secondary audiences– Determine measurable usability objectives– Discuss expectations and requirements– Timeline and project plan
Planning
1. What is the purpose of the site? – Why are we building a site? – What are the goals of the site?
2. Why are we developing a web site? – What does success look like? – How will we know when we have been successful?
3. Who are we developing the site for? – Who is the site for? (User characteristics)
– Why will they come to the site? (User needs, interests and goals)
– When/where will they access the site? (User environment)
– What will they do on the site? (User tasks and priorities of tasks)
Planning
4. What are our usability objectives? – Effectively (Ability to accomplish tasks)
– Efficiently (Ability to accomplish with speed and ease)
– Satisfying (Pleasing to users)
5. What are project team’s preferences?– Is there a vision of what the site will do and/or look like?
– Are there any restraints or mandates for the site?
– Are there any web site styles you prefer?
6. Timeline and Project Plan
Planning
• Difference between business vs. user goals– E-Commerce Sites
• To generate revenue
• To research products and prices
– Intranets• Improve employee communication
• Get work done fast
– Information-Based Sites• To provide evidence-based research information
• To find information
• Methods of Data Collection– Personal Interviews– Contextual Inquiries– Focus Groups– Surveys– Support Line/Phone Calls– E-mail– Web Logs
Gather User Data
• What is it?– Discussion with users to learn about their goals, tasks
and environment
• How to do it?– Use open-ended questions– Probe on problems – Do not give positive or negative signals
• Benefits/Disadvantages?– Learning from users first-hand– Users do not always recall processes accurately– What users say and do are not always the same
Personal Interviews
• What is it?– Observational method– Improves understanding of existing processes and steps
• How to do it?– Observe users in their natural environment– Observe users carrying out tasks, naturally– Do not give positive or negative signals
• Benefits/Disadvantages?– Relies on observation, not users’ recollection– Gather data users may not be able to vocalize– Time-consuming
Contextual Inquiries
"Which of the following best describes you?"
CancerNet NCI
N % N %
Family/Friends 169 28 414 27
Cancer Patients 85 14 266 17
Educators/Students - - 155 10
Researchers/Scientist 41 7 97 6
Nurse (non- Oncology) 15 2 42 3
Oncology Nurse 14 2 34 2
Oncologist 60 10 33 2
Physician (non- Oncology) 22 4 32 2
J ournalist/Media Professional - - 31 2
Librarian 29 5 30 2
Patient Advocate 8 1 26 2
Other 91 15 209 14
Not specified 81 13 157 10
615 1526
Surveys
"What information are you looking for?"
Major Categories CancerNet NCI
I nformation on specific type of cancer 23% 25%
Treatment information 19 17
Symptoms, causes, risk factors….. 8 5
Statistics (e.g. incidence rates, survival) 3 5
Clinical Trials 11 5
Access to other resources (e.g. treatment
facilities, physicians) 3 4
Drug information 3 4
NI H Organization (e.g. mission, employment) - 3
New treatments 5 3
Ordering NCI publications 2 3
Recent findings - 2
Type of tumor (not by cancer name) 7 2
Cancer literature 5 1
Patient support 4 2
Side eff ects 3 2
Surveys
Gather User Data
• Need to design for user not let user design for you• We’re developing a website. What tasks would you
like to be able to do on a website for health communications planning? What would you like to be able to find?
• What are the four most important steps in planning a health communication campaign? What are some challenges you encounter when planning campaigns?
• Users have limited amount of technical knowledge
Translating Data into Design
• User Profiles / Personas– Characteristics about user, environment, and tasks– List or narrative
• Task Analysis– Lists of tasks prioritized by frequency and importance– Process Flows
• User and Site Goals– List of measurable goals
• Design Considerations– Guidelines based in research– User considerations
User Profile or Persona
1. User Characteristics
2. Environmental Characteristics
3. Goal & Task Characteristics
User Profile or Persona
• User Characteristics– Demographics
• age
• gender
• ethnicity
• income
• language
• disability
• occupation
• education
• learning needs
• internet/computer experience
User Profile or Persona
• Environment Characteristics– Location
• home/work
• indoor/outdoor
– Workspace
• cramped/spacious
• bright/dim lighting
– Hardware
• monitor size
• connection speed
• video/sound card
– Software
• browser
• resolution
• plug-ins
User Profile or Persona
• Goals / Tasks Characteristics– Tasks
• information-based
• functionality-oriented
– Number
• how many
– Flow
• order of tasks
– Importance
• most to least
– Frequency
• most to least
Sarah Parker
Sarah is a Senior Marketing Specialist with seven years of experience planning health campaigns.
She works in a large office where she handles multiple projects. She is constantly busy and struggles with a limited budget.
Sarah can easily identify the steps necessary to carry out each project. She doesn’t need help determining how to approach the planning process and mainly uses the various resources available as a reference.
Sarah would appreciate any tool or resource that could help her get her work done faster and more efficiently.
User Persona
Maria Green
Maria is a junior specialist and is relatively new to the health communication planning field.
Although Maria faces many of the same challenges as Sarah, including lack of time, constrained budgets, insufficient support, she has less experience than Sarah.
Unlike Sarah, Maria does not have any formal training in planning and is less familiar with the steps required to develop a plan. Maria relies heavily on resources to help with her work.
She currently used an interactive tool, but has an older computer that cannot handle all of the features in the program. In addition, Maria has a very slow internet connection which limits the resources she can access online.
User Personas
• Task List– Lists of tasks prioritized by frequency and importance
• Task Flow Diagrams– Drawings that show tasks in the order performed
• Task Scenarios– Narrative descriptions of a task
• User and Task Matrix– Matrices that show which users perform which tasks
Task Analysis
User Goals
• Efficiency– How well should the user be able to perform?
• Within a certain time• With a certain degree of accuracy (error rates)• For a certain percentage of users
• Learning– How long should it take a user to learn the interface? – After not using the interface for awhile, how long should it
take for the user to get back up to speed?
• Satisfaction– How will the interface avoid inducing user boredom,
discomfort, frustration, or work overload?
User & Site Goals
• Measurable Success Factors for the Site– Increase revenue generated by the site by __% by ___. – Increase number of registered users by __% by ___. – Reduce number of customer service calls from ___ to ___
by ___.
• Measurable Success Factors for Users– 75% of all users will be able to load the software correctly
on the first attempt in less than 10 minutes.– 75% of users will be able to successfully locate the “Contact
Us” page on the web site with a minimum of two incorrect clicks and in less then 2 minutes.
– 75% of user will have a satisfaction rating of 7 or above (on a 10-point scale) after using the site for the first time.
• Based on needs of users, e.g.,– Priority of tasks and content– Organization of information, taxonomies, labeling– Font size, color palette, contrast, legibility, – Writing style and level– Layout, screen density– Complexity, accelerators– Training, help, tooltips, error management
Design the Initial Prototype
• Guidelines based on research – Enhance scanning by providing clear links, headings,
short phrases and sentences, and short paragraphs – Provide most important information at highest point on
page– Don’t rely on expert evaluations (heuristic reviews) to fix
site problems– Use parallel design to create prototypes
• Research-based Web design & usability site– http://usability.gov/research
Designing the Initial Prototype
Usability Defined
• Usefulness– Degree to which users can successfully achieve goals
• Effectiveness (ease of use)– Ability of users to accomplish goals with speed & ease
• Learnability– Ability to operate the system to some defined level of
competence after some predetermined amount/period of training
• Satisfaction / Likeability– Attitude of users, includes perceptions, feelings and
opinions of the product
Booth, Paul. An Introduction to Human-Computer Interaction. London: Lawrence Erlbaum Associates, 1989.
Usability Testing
• Planning– Define goals– Determine who will participate– Select appropriate tasks– Plan logistics
• Conducting– Assign roles– Collect data
• Analyzing & implementing results– Prioritize findings– Implement & retest
Usability Testing
• Define usability goals– Performance
• Measurements– speed
– errors / success
– learning, training time
– Preference• Measurements
– user satisfaction
• Determine who will participate– User profiles
• Match characteristics from user analysis• Select representative group of users
– Selecting participants• Recruiting – recruitment firms, databases, conferences• Numbers – target numbers, floaters• Schedule – allow recoup time• Pre-Questionnaires – profile of participants• Incentives – consent & payment form
Usability Testing
• Select Appropriate Tasks
– Task List • Prioritize by
– Frequency
– Importance
– Vulnerability
– Readiness
• Ensure each task is measurable. Define measures ahead of time
• Include pathway information for observers• Conduct pilot test to look for give-away wording or
confusing scenarios
Usability Testing
Usability Testing
• Create Scenarios– Find two clinical trials that relate to breast cancer
prevention– View a demonstration of how this site works– Create an account on this site– What are today’s rates for a 25-year fixed-rate
mortgage?
Usability Testing
• Plan Logistics– Test location
• Lab, office, usability / market research facility– Prepare for observers
• One-way glass observation room• Projected onto screen in adjoining room
– Traffic flow of participants– Audio & video recording
• Value of highlight tape
Usability Testing• Plan Logistics
– Materials needed• Screening questionnaire• Background questionnaire• Pre- and Post-test questionnaires• Video release form• Incentive signature form • Schedule• Facilitator’s guide• Participants’ scenarios• Observers’ scenarios (with pathways included)
• Data collection materials (with measurements defined)
Usability Testing
• Assigning roles– Facilitator
• Next to participant or in adjoining room• Role (see handout)
– Observers• Role (see handout)
Usability Testing
Video Highlight Tape
Usability Testing
• What makes a good facilitator?– Clear understanding of goals– Good listening skills– Impartial – not wedded to a particular design – Quick thinking– Flexible and adaptable– Put people at ease & get them to open up– Able to ‘walk in shoes’ of others– What else?
Usability Testing
• Collecting data– Performance (Objective)
• Usually Quantitative– Time to complete a task– Time to recover from an error– Number of errors– Percentage of tasks completed successfully– Number of clicks– Pathway information
– Preference (Subjective)• Usually Qualitative
– Preference of versions– Suggestions and comments– Ratings or rankings (can be quantitative)
Usability Testing
• Analyzing the data• Quantitative data
– Statistics (number of clicks, errors rate, time, etc.)
– Look for trends
• Qualitative data– Attitude, comments
Usability Testing
• Prioritize findings– Usability goals met?
• Prioritize tasks that performed the worst according to goals
• Prioritize findings by frequency / importance
• Prioritize recommendations by feasibility
• Implement and retest!
Participants did not understand the
difference between “other” and “related”
Participants did not notice the instructions.
Participants did not understand how this
list box worked, because is it possible to select both benign and malignant tissue.
Participants thought the default number
was too large.
Other Evaluation Methods
• Card Sorting• Paper Prototyping• Heuristic Evaluations / Usability Reviews
Card Sorting
• What is it?– Explores how users group items– Helps to develop structures that are logical to users– Maximizes probability of users finding info– Identifies items that are hard to categorize– Identifies terms that are interpreted differently by different
types of users
Card Sorting
• How to do it?– Participants are given a set of cards, with one item per card– Participants sort cards (content items) into logical categories
and assign labels to categories – Participants may sort cards into pre-defined categories– Participants may be asked to rename the individuals cards
or think of synonyms
• Benefits/Disadvantages?– Helps to develop categories that are logical to users– Helps to identify the items that need to be renamed– Helps with terminology– Sometimes it is difficult to analyze, tools have limitations
Paper Prototyping
• What is it?– Low-tech method that allows you to test early, before
design and development
– Paper drawings of pages • How to do it?
– Participants are shown the paper prototype and given scenarios
– Participants are asked to point to where they would click
• Benefits/Disadvantages?– Helps to find problems early– Low-cost, saves development time– Help determine affordance (does it look clickable)
Heuristic Evaluation
• What is it?– Expert review of web site based on established usability
guidelines
• How do you do it?– Conducted by usability expert (best to include multiple
reviewers)– Experts review site for compliance/noncompliance with
established principles
• Benefits/Disadvantages?– Provides a reference of issues to be tested– Subjective– Not always accurate, identifies false positives– Not real users
Research and Resources
• Usability.gov Web Site– Online resource for those involved in Web site design
• Research-Based Web Design/Usability Guidelines– Topics: Web site goals, alignment, headers, fonts/line
length, frames, graphics, scrolling, download times, accessibility, page size, controls…
– Format: Guideline, comments, strength of research, source, graphic examples (do this/don’t do that)
• U-Group– Provides tips, tools, and information about developing
useful, usable Web sites and other health information systems
Contact
Communication Technologies Branch (CTB)Office of Communications • National Cancer Institute
Cari A. Wolfson
6116 Executive Blvd, Suite 3048A
Rockville, MD 20852
301/496-1308 • fax: 301/435-6069