By Erin Weigel | Senior Designer at Booking.com “We tested that, and it failed.” This typical excuse is rampant in the world of A/B testing, but it can overlook the fact that a concept in and of itself is fundamentally different from the execution of a concept. In this talk Erin shares insights about why A/B tests fail from over 1,100 experiments she's run at Booking.com over the past 4 years.