Log in or create a free Rosenverse account to watch this video.
Log in Create free account100s of community videos are available to free members. Conference talks are generally available to Gold members.
UX Lessons from running more than 1,200 A/B Tests
Summary
Knowing how to solve the right problem is only one small part of the product-success equation. And nailing the execution is harder than most people think. As Erin says in this talk, “There are far more ways to fail than there are to succeed” when it comes to experimentation. To help you learn, Erin shares some of the silly mistakes she made while A/B testing her designs. That way you can avoid those pitfalls as you work to make your digital product better—not just different.
Key Insights
-
•
Nine out of ten AB tests at Booking.com fail, but the few that succeed compound into massive growth.
-
•
Execution often fails on good ideas rather than the ideas themselves.
-
•
Technical details like page load time can negate positive design changes if not carefully managed.
-
•
Edge case bugs in different languages or currencies can silently kill conversions.
-
•
Minor typography choices, such as switching from Times New Roman to Arial, have a large impact on conversion.
-
•
Using system fonts improves legibility and page load speed, positively affecting conversions.
-
•
Tracking should only include users exposed to the tested change to avoid noisy data.
-
•
Qualitative user research drives many experiment ideas by revealing real user challenges.
-
•
Guardrail metrics like customer service calls and loyalty prevent short-term wins from harming long-term value.
-
•
Products should be retested over time as technology and user behaviors evolve, since what fails today may succeed tomorrow.
Notable Quotes
"I’m actually a really big failure — nine out of ten tests fail with no positive measurable impact."
"Compound effect means good upon good upon good eventually builds to incredibly fast growth."
"If a problem keeps coming up, it’s usually the execution of the idea that’s failing, not the concept."
"Increasing page load time by three seconds can nullify all your design improvements."
"Picking the wrong size image can impact customer experience as much as what you see on screen."
"There are as many versions of the website as stars in the sky because of language, currency, and device variations."
"No tracking is perfect because numbers tell you what likely happened, but not why it happened."
"System fonts load faster, improve legibility, and outperform fancy brand fonts in conversion."
"Guardrail metrics help catch unintended consequences like increased customer service calls despite higher conversions."
"You can’t fail 90 times out of 10 without laughing at yourself to keep going."
Or choose a question:
More Videos
"If a bot can’t handle the query, it goes to a human—it's like Mechanical Turk for AI."
Greg NudelmanDesigning Conversational Interfaces
November 14, 2019
"This is all wheat, no shafts, lessons drenched in hard work and real experience."
Bud CaddellTheme 2 Intro
September 30, 2021
"ESPN’s site is a great example of poor hierarchy and alignment — it’s hard to know where to start or where to go next."
Billy CarlsonPro-level UI Tips for Beginners
September 9, 2022
"We need to reframe compensation around reciprocal exchange, not just monetary incentives."
Robert Fabricant Sahibzada Mayed Nidhi Singh RathoreIndustry junctures: Paths forwards for UXR and the critical decisions that get us there [Advancing Research Community Workshop Series]
October 2, 2024
"It’s surprisingly easy to bring in your own UX or marketing personas to run simulated testing with VO Pulse."
Gillian Salerno-Rebic Mark MicheliFrom Insight to Impact: How JourneySpark Used WEVO Pulse + Pro to Drive a 50% Lift in Ad Engagement
June 11, 2025
"Designers bring a unique cultural perspective to multidisciplinary scientific teams, helping interpret and communicate complex data."
Victor Lombardi Ted Booth HK Dunston Andrew OtwellBridging Design and Climate Science
February 14, 2024
"Leading change in a century-old company is a very different challenge."
Lada GorlenkoTheme 1: Intro
January 8, 2024
"The more specific a story gets, the more universal the themes are felt by everybody."
Dan WillisEnterprise Storytelling Sessions
June 3, 2019
"My race has been treated like guinea pigs for most of our existence."
Emily Williams Nora FioreWhen UX Research and Institutional Racism Collide: A Case Study
March 12, 2021
