Usability and Eye Tracking Marco Pretorius Usability Manager & - PowerPoint PPT Presentation

Usability and Eye Tracking Marco Pretorius Usability Manager & Researcher UNISA: School of Computing

Agenda • Introduction – What is usability? – User-centered design – Eye tracking • Benefits and ROI • UNISA usability laboratory • Studies and results • Other Interesting figures and examples • Questions

Introduction

What is usability? • Lack of usability: – Play video

What is usability? • Usability means making products and systems easier to use, and matching them more closely to user needs and requirements • ISO9241: Usability is the – effectiveness – efficiency and – satisfaction – with which specified users – achieve specified goals – in particular environments

What is usability? • Effectiveness – Can users achieve what they need by using the product? • Ease of learning – How fast can a user who has never seen the interface learn to use it? • Efficiency of use – How fast can users complete the task? • Memorability – Can users remember enough to reuse the interface effectively? • Error prevention – Can users complete tasks without making errors? • Satisfaction – How much does the user like using the system?

User-centered design • ISO 13407: User-centered design is characterised by: – the active involvement of users and a clear understanding of user and task requirements – an appropriate allocation of function between users and technology – the iteration of design solutions

User-centered design • Goal – To develop easy-to-use products – that lead to increased user satisfaction – meet your organizational or business objectives • Difference between other design philosophies – user-centered design tries to optimize the user interface around how people can, want, or need to work – rather than forcing users to change how they work to accommodate the system or function

User-centered design • ISO13407 • 4 essential activities in UCD http://www.upassoc.org/usability_resources/about_usability/ what_is_ucd.html

User-centered design • 1. Specify context of use – Identify the people who will use the product, what they will use it for, and under what conditions they will use it

User-centered design • 2. Specify requirements – Identify any business requirements or user goals that must be met for the product to be successful

User-centered design • 3. Design – Producing designs and prototypes – This part of the process may be done in stages, building from a rough concept to a complete design.

User-centered design • 4. Evaluation – The most important part of this process is that evaluation - usability testing with actual users - is as integral as quality testing is to good software development

User-centered design • The stages are carried out in an iterative fashion – Cycle repeated until the project's usability objectives have been attained – Critical - participants accurately reflect the profile of your actual users – Talk directly to the user at key points in the project to make sure the site will deliver upon their requirements

User-centered design • Methods used: – Requirements and data gathering • Interview • User observation • Contextual inquiry • User group meeting • Focus groups • JAD sessions • Surveys • Bulletin boards/discussion groups • Web logs

User-centered design • Methods used: – Usability testing • Task walkthroughs • Performance-based tests • Heuristic evaluations • Preference tests • A-B testing

What is usability? • Usability testing involves – measuring the performance of users on tasks with regard to • the ease of use, • the task time, and • the user‟s perception of the experience • of the product, software application, website or systems – Based on Performance – Purpose: Feedback

What is usability? • What Usability testing is not – Not market research – gathering opinions – not just a milestone to be checked off on the project schedule – not finished when the last participant leaves • Involves systematic observation under controlled conditions to determine how well people can use the product – watching people trying to use something for its intended purpose • Consider the findings, set priorities, and CHANGE the prototype or site based on what happened in the usability test

Eye tracking • A technique to determine eye movement and eye fixation patterns of a person • The human eye moves by alternating between • Saccades • Quick movement of the eye • Move focus from one area to the next • Fixation • Time spent looking at the newly found area

Benefits and ROI

Benefits and ROI • 63% of software projects exceeded their estimates because (Lederer and Prassad ‟92) • Frequent request for changes by users • Overlooked tasks •Users‟ lack of understanding of their own tasks • Insufficient user <> analyst communication • 80% of software life cycle costs occur during maintenance phase (Pressman „92) • 80% of maintenance comes from unforseen/unmet user requirements (Martin „83) • 60% of maintenance phase is due to re-work because user requirements were not clear at start (Standish „83)

Benefits: usability • Benefits for an organisation: • Save on development and maintenance by: • Saving on development costs • Decreasing the development time • Reducing maintenance costs • User-centred design • Usability testing very early and throughout development • With a rigorous user-centered methodology, you can ensure successful, on-time delivery – and avoid the rework that's necessary later if you don't talk to users in the first place

Benefits: usability • Benefits for an organisation: • Increase Total Revenue by increasing the number of: • Transactions • Conversion and hence turnover • Returning customers • New customers through word of mouth advertising

Benefits: usability • Benefits for an organisation: • Stimulate the use of the website by: • Increasing the success ratio for a visitor • Decreasing the number of errors and show stoppers • Increasing efficiency for users (less time to complete a task) • Increasing users satisfaction

Benefits: usability • Benefits for a user: • Understand a site faster and achieve their goals faster • Have a positive experience using the website • Develop trust in the company • Perform tasks without help from telephone or e-mail • http://www.2c.nl/en/what_is_usability/advantages_usability_test.php

Benefits: combination • Usability and eye tracking: • All the benefits of traditional usability results • Eye tracking can add new and interesting insights • Provide insights that are not available from traditional usability testing methods • Scan paths; Pattern of fixations • Time spent looking at various display elements • Insight into deployment of visual attention • Participant strategies

Benefits - Examples: • Human Factors International • Staples.com • 67% more repeat customers • 31-45% reduced drop-off rates • 10% better shopping experience • 80% increased traffic • Increased revenue – sales up by 491% • Utility company in Canada – Intranet • Training hours from 8 hours to 15 minutes • Energy company in US – Intranet • 300 support calls per day to ZERO

UNISA usability lab

UNISA usability lab • A usability laboratory is a state-of-the-art facility designed to support the observation of HCI • Users are brought into a controlled environment, in which they are asked to do specific tasks within specific timeframes • Evaluators – observe the problem(s) the participant might have – videotape the participant – analyse the data

UNISA usability lab • Observer room • Participant room • Separated by one-way mirror • Tobii 1750 eye tracker • Audio and Video Recording equipment • Event logging, eye tracking software

Typical data collected • Live video recordings – Screen – Mouse and keyboard movements – Facial expression • Audio • Eye tracking video with cursor • Eye tracking data files • Post-test questionnaire • Monitoring of tasks

Usability Measures Effectiveness • Task completion rate • Number and percentage of tasks completed with • and without assistance Error rate recovery • Efficiency • Task completion time • Real-time events • Satisfaction • Post-test questionnaire •

Eye tracking measures Number of fixations • Fixation duration • Number of fixations on each Area of Interest • Number of gazes on each Area of Interest • Time to 1 st fixation on target Area of Interest • Scan path •

Studies and results

MyUnisa – Assignment Submission Tool • Participant Profile – Full-time UNISA students who have to submit assignments online – 10 participants – 5 male, 5 female – 7 different languages – 5 expert, 5 non-expert Web users

MyUnisa – Assignment Submission Tool Task example: Submit a PDF file • Task completion: 70% • Assistance needed: 40% • Errors made: 100% • Median task completion time: 115.60 seconds • Play video: (PDF)