Eye Tracking the User Experience

Eye Tracking the User Experience


198 Pages


Eye tracking is a widely used research method, but there are many questions and misconceptions about how to effectively apply it. Eye Tracking the User Experience—the first how-to book about eye tracking for UX practitioners—offers step-by-step advice on how to plan, prepare, and conduct eye tracking studies; how to analyze and interpret eye movement data; and how to successfully communicate eye tracking findings.



Published by
Published 15 November 2013
Reads 27
EAN13 9781457103025
Language English
Document size 8 MB

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Aga Bojko


Eye Tracking the User Experience

A Practical Guide to Research

By Aga Bojko

Rosenfeld Media, LLC

457 Third Street, #4R

Brooklyn, New York

11215 USA

On the Web: www.rosenfeldmedia.com

Please send errors to: errata@rosenfeldmedia.com

Publisher: Louis Rosenfeld

Managing Editor: Marta Justak

Development Editor: Edward Wade

Copy Editor: Marta Justak

Interior Layout: Danielle Foster

Cover Design: The Heads of State

Cover Illustrator: Martha Rich

Indexer: Sharon Shock

Proofreader: Sue Boshers

© 2013 Aga Bojko

All Rights Reserved

ISBN: 1-933820-10-1

ISBN-13: 978-1-933820-10-1

LCCN: 2013934832

Printed and bound in the United States of America


Who Should Read This Book?

This book is a practical guide that will benefit anyone wanting to learn how to conduct eye tracking studies in order to evaluate and improve the user experience of products and interfaces.

This book is for you if:

• You are considering adding eye tracking to your research but are unsure if it is going to be of value to you.

• You recently purchased an eye tracker and are thinking, “Now what?”

• You’ve been conducting eye tracking studies for a while but would like to expand your repertoire of capabilities.

This is not a UX research handbook; its contents assume a certain level of knowledge and experience with UX evaluation methods on the part of the reader. Therefore, if you are just starting out in the field, you should first learn the basics of formative and summative testing, and then come back to this book.

What’s in This Book?

This book contains everything you need to know to successfully conduct an eye tracking study and obtain useful information from it. The material is divided into four parts:

Part I: Why Eye Tracking?

Before jumping into the how, it’s necessary to establish what eye tracking is, how it works, and most importantly, why even bother doing it. The two chapters in Part I set the stage for the remainder of the book and explain the types of actionable UX insight that can result from eye tracking.

Part II: Study Preparation

Because this book subscribes to the “think first, track later” philosophy instead of the risky and unfortunately common “track first, think later,” Part II is the longest of the four. These six chapters cover everything from preparing the stimuli and tasks for an eye tracking study to figuring out how many participants to recruit and which measures to collect.

Part III: Data Collection

These are nuts and bolts of eye tracking in the narrow sense of the term. Part III explains what to do during study sessions to end up with highquality eye tracking data.

Part IV: Analysis and Reporting

Part IV describes what should happen with the data once they are all in your hands: how to prepare them for analysis and how to distill useful information from them. Both qualitative and quantitative analyses are accounted for in the four chapters that comprise this last section of the book.

Not all of the content in this book is specific to eye tracking. Some applies to non-eye tracking studies as well. The coverage of the more general topics corresponds to the questions that often come up in the context of eye tracking, as well as common mistakes. A good example of this type of material is the in-depth discussion on sample size in Chapter 8. While the method of determining sample size for eye tracking studies is the same as for non-eye tracking studies, the topic had to be included because of the frequent inquiries and widespread misconceptions surrounding the number of participants needed for eye tracking. The far less controversial topic of recruiting procedures, on the other hand, was not given much coverage outside of mentioning a few eye tracking-specific issues.

What Comes with This Book?

This book’s companion website (Imagerosenfeldmedia.com/books/eye-tracking-the-ux/) contains a blog and additional content. The book’s diagrams and other illustrations are available under a Creative Commons license (when possible) for you to download and include in your own presentations. You can find these on Flickr at www.flickr.com/photos/rosenfeldmedia/sets/.


Do I need eye tracking in my research?

It’s like asking “Do I need a microscope?” You don’t need one to see the dust bunnies under your bed, but you do if you want to find a dust mite. It all depends on what you are looking for. So maybe you do need eye tracking, maybe you don’t. Let Chapter 2 be the judge.

Eye tracking is not useful. I’ve seen heatmaps, and they didn’t tell me much.

First, this is not a question. Second, eye tracking is so much more than heatmaps. (As described in Chapter 11, those should only be used in a supplemental role.) Third, whoever gave you heatmaps in place of actual data analysis needs to read this book. Cover to cover. I will gladly hold on to their eye tracker until they are done.

How many participants should I get for an eye tracking study?


Just kidding. As much as you’d like a simple answer, there isn’t one. If you are ready for the truth about sample size and all the factors that it depends on, make yourself a sandwich and proceed to Chapter 8.

Which eye tracking measures should I use?

None, if your study is purely formative, and you are just looking for usability issues. But if you are conducting summative research, you should choose your measures based on the cognitive processes you’re trying to assess. There is no one measure that is perfect for every study, not even my favorite—average fixation duration. Chapter 7 will gently guide you in your measure selection process.

How do I analyze the data?

Brownie points for asking the question! Yes, data need to be analyzed before they can provide useful information. You don’t just generate some heatmaps or scanpaths and call it a day. First, you carefully prepare your data for analysis. (Data cleansing is key.) Then, depending on the type of analysis—qualitative or quantitative—you systematically inspect visualizations or calculate statistics. For step-by-step instructions, refer to Chapters 10 through 13.

Why do you keep saying that eye tracking is “just not that special?”

Because as a method, it really isn’t. An eye tracking study should be subject to the same research principles as any non-eye tracking UX study. There are, of course, a few additional considerations, but the core is always the solid and well-established scientific method. Once everyone realizes that, eye tracking will become a more rigorous and systematic undertaking in the UX field than it may have been thus far. And that’s the goal of this book.


Eye tracking has always seemed very promising. After all, in our profession we spend a lot of our time trying to read users’ minds. One of our most powerful tools—usability testing—consists simply of asking users to think aloud while they use our products so that we can understand where they’re getting confused. I describe it as trying to see the thought balloons forming over users’ heads, especially the balloons that have question marks in them. They’re the ones that tell us what needs fixing.

Eye tracking is naturally appealing to us because it holds out the promise of another window into the mind: the semi-magical ability to know what people are looking at. And since there seems to be a strong (though not absolute) connection between what people are looking at and what they’re paying attention to, eye tracking can provide another set of useful clues about what they’re thinking and why the product is confusing them.

At the very least, it promises to answer questions like “Did they even see that big button that says ‘Download?’” If the eye tracking shows that people aren’t seeing it, then we know that they can’t possibly act on it, and we should probably give some thought to making it more prominent somehow.

That’s why eye tracking is one of the three technologies I’ve been waiting for, for a long time.1 In fact, when I wrote Don’t Make Me Think, it was going to be based in part on some eye tracking research I was going to do. But it turned out that the technology at the time—particularly the software to analyze the mountains of data that eye trackers produce—just wasn’t up to the task. Fifteen years ago eye trackers were for specialists who spent all their time feeding them their specially prepared fuel pellets, writing their own analysis software, and trying to read the resulting runes.

Then came the millennium and a quantum leap forward by the manufacturers. All of a sudden, instead of requiring programming skills, bailing wire, and a soldering iron, eye trackers worked right out of the box. And they came with software that let almost anyone—anyone with $30,000— generate impressive output, especially (God help us!) heatmaps.

Over the years, I’ve sat through countless demos and presentations, and tried to read everything that was written about eye tracking and UX. At one point, one of the manufacturers was even nice enough to give me a loaner for a few months, so I had the chance to do a little experimenting myself. The upshot is that I’ve always known a lot about eye tracking for someone who doesn’t actually do eye tracking.

And here’s what I know:

Eye tracking is sexy. Harry Brignull once did a presentation that drew an analogy between eye trackers and the shoe-fitting fluoroscopes that were used in shoe stores from the 1920s to the 1960s.2 Your child would put his or her feet in an opening at the bottom of the machine, and you could peer in and see the bones inside, giving you the comforting knowledge that the shoes weren’t going to warp your child’s tender feet. It was fascinating, it was science (not opinion), and it offered the promise of proof. And it had lots of sizzle.3 Heatmaps have the same kind of sizzle.


It sells. Even though we can all agree in retrospect that the shoe-fitting fluoroscope was probably not a good idea, it sold shoes. And blinding people with science still works: eye trackers sell UX services. You can probably charge more if your deliverables include some heatmaps, whether they show anything that’s useful or not.

It seems easy. But it’s not. It’s no trick nowadays to do some eye tracking and create compelling graphics that make it seem like you’re proving something. But actually knowing what you’re doing takes time, experience, and learning.

It’s hard to learn how to do it well. There have been tons of academic papers and manufacturers’ white papers, but no one has produced a how-to book for practitioners.

Enter Aga.

Actually, I’d like to take a tiny bit of credit for this part. I’d heard Aga speak several times over the years, so I knew that she always had the smartest things to say about eye tracking and UX. Then I read an article she wrote for the UX magazine and discovered that she was a really, really good writer. So I told Lou Rosenfeld he needed to get her to do a how-to book. Now that it’s here, I feel a little like a proud uncle. Or maybe a matchmaker.

Believe me, you’re in good hands. Aga really knows her stuff, and she’ll tell you just what you need to know. This is, as she’s described it, “The book I wish I’d had when I was starting out doing eye tracking.” What more can you ask for?

BTW, if I were an eye tracking manufacturer, I’d buy a few hundred copies and give them away to all my customers and potential customers. And then I’d loan Steve Krug another eye tracker.

—Steve Krug
Author of Don’t Make Me Think


Why Eye Tracking?




Eye Tracking: What’s All the Hoopla?

What Is Eye Tracking, Anyway?

Why Do the Eyes Move?

How Do the Eyes Move?

Why Should You Care Where People Look?

Why Do People Look at What They Look At?

Applications for Eye Tracking

Tool or Method?


Eye tracking, which is the process of identifying where someone is looking and how, has generated a great amount of interest in the user experience (UX) field since the beginning of the twenty-first century when the technology started becoming more widely accessible. Once a novel addition to the UX research toolbox, used by only a handful of early adopters, eye tracking is now frequently employed to help evaluate and improve designs (from websites to product packaging) at various stages of the development cycle.