Usability testing

楊政達

(1) 期末Project規劃預告(2) 今天 : Usability Testing

期末 Project• 1/10 or 1/17???

• 原型與使用測試報告– App 的草創、構想、測試、發展、定案過程

等等

• 發表–App 形象影片• 至多 1 分半 ~ 2 分鐘

• 可以是使用介紹、 App 概念等等

• 廣告 ! 推銷 ! 吸引人 !

• 呈現形式不拘 :–搞笑的 Absurd Smartphone APP–情境的 Google Search App –….

Usability Testing

Usability is often an oversight

Why does usability matter?

• Usability can save time, money and lives

• On the web, usability is a precondition for survival

• On commercial off the shelf software applications, usability can determine market share

Bad website example

What is usability?

• ISO 9241-11 – “the extent to which a product can be used

by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use.”

• Usability Professionals Association – Is an approach that incorporates direct user

feedback throughout the development cycle in order to reduce costs and create products and tools that meet user needs

• Steve Krug, – “..making sure that something works

well: that a person of average (or even below average) ability and experience can use the thing --- for it’s intended purpose without getting hopelessly frustrated”

Benefits of Usability• Increased productivity

• Decreased training and support costs

• Increased sales and revenues

• Reduced development time and costs

• Reduced maintenance costs

• Increased customer satisfaction

Commonality of usability definitions

• A user is involved

• That user is doing something with a product, system, or other thing

User-centered design (UCD)

User requirements analysis

Conceptual design…

User-centered design (UCD)

• Focus on users’ needs, tasks, and goals

• Invest in initial research and requirements– Identify your target audience and

observe them– Let users define product requirements

• Iterative design process

• Observe real target users using the system

What is usability testing?

• is a technique used to evaluate a product by testing it on representative users

• test users will try to complete typical tasks while observers watch, listen and takes notes

Goal

• identify any usability problems

• collect quantitative data on participants‘ performance

• determine participant's satisfaction with the product

Can usability be measured?

• Using usability metrics – Effectiveness – being able to complete a

task

– Efficiency – amount of effort required to complete a task

– Satisfaction – degree to which the user is happy with his/her experience

5 E’s of usability • Effective: How completely and accurately the

work or experience is completed or goals reached

• Efficient: How quickly this work can be completed

• Engaging: How pleasant and satisfying it is to use

• Error Tolerant: How well the product prevents errors and can help the user recover from mistakes

• Easy to Learn: How well the product supports both the initial and continued learning

Steps for user testing

• Plan user tests

• Conduct user tests

• Analyze findings

• Resent findings

• Modify and retest designs

Formative testing

• during the development of a product• to mould or improve the product• Iterative

• Output– Usability problems and suggested fixes– Highlight videos

Summative testing• At the end of a development stage• To measure or validate the usability of a product• "How usable is this product"• To compare against competitor products or

usability metrics• To generate data to support marketing claims

about usability

• Output– Statistical measures of usability– Reports or white papers

Benefits of usability testing

• Identify and rectify usability deficiencies prior to product release

• Intent to create products that: – Are useful to and valued by target

audience – Are easy to learn – Help people to be efficient and effective – Are satisfying (delightful) to use

Eliminating design problems and frustration

Improving profitability

Follow the principle

• Many usability tests are worthless. Researchers recruit the wrong kind of participants, test the wrong kind of tasks, put too much weight on people's opinions, and expect participants to generate design solutions.”

Test participants

• Participant’s background and abilities should be representative of your product’s intended user

• user profile – person with the relevant behavior, skills, and knowledge who will use your product.

How many users to test?

• 6-8 users per test or 5 users spread over multiple tests

• little ROI in testing more than 9 users

Quantitative tests – test 20 users

Testing locations

• Lab

• Office

• bar, café

• remote testing

Usability lab

Testing in a conference room

Informal usability testing

Levels of Prototyping

Sketch / Mock-up / Final Prototype

Usability testing process

Planning your test • Decide what to test –What are your objectives –What data will you collect

• Who is your target audience? –Write a screener

• Decide on test location – Remote, lab, conference room, coffee

shop

• Write tasks that meet your objectives

Deciding what to test• Understand requirements – What do users want to accomplish? – What does the company want to accomplish?

• Determine the goals – What tasks does the website or application

support?

• Decide on the area of focus – Tasks that have the most impact on your site – Typical tasks – Most critical tasks

Test plan• Purpose, goals, and objectives

• Participant characteristics

• Method (test design)

• Task list

• Test environment, equipment and logistics

• Test moderator role

• Evaluation measures (data to be collected)

• Report contents and presentation

Recruiting users

• Recruit internally or outsource to agency?

• Sources of test candidates – Your own company’s list of existing

customers – Referrals from sales and marketing – Advertising on Craigslist – Company’s web site or blog – Societies and Associations

Prepare test materials• Orientation script

• Background questionnaire

• Recording consent

• Pre-test questionnaire

• Data collection tools

• Task scenarios

• Post-test questionnaire

• Debriefing topics

Task types• First impression questions – What is your impression of this home page or

application?

• Exploratory task – Open-ended / research-oriented – e.g. Find a cellular phone plan for yourself

• Directed tasks – Specific / answer-oriented – e.g. Find contact information for customer

support

Metrics• Task success

• Task time

• Errors

• Efficiency – Number of steps required to perform a task

• Self-reported metrics – Likert scale – Do you prefer A or B? – Questionnaires

Prepare the prototype

Conducting a Test

Test moderator conduct

• Put the participants at ease

• Give participants time to work through hindrances

• Offer appropriate encouragement

• Ask non-leading questions

Thinking aloud methodology

• Observe user behavior

• Listen to user feedback

• Facilitator stays quiet, observes, take notes

• Test one user at a time

• Mainly qualitative

Debriefing

• Exploring and reviewing the participant’s actions during the test

• Goal – understand why every error, difficulty and omission occurred for every participant for every session.

• Debrief with observers too.

Analyze and present