Building an A/B Testing Analytics System with R and Shiny
1. Building an A/B Testing
Analytics System with R and
ShinyEmily Robinson
@robinson_es
2. About Me
➔ Data Scientist at DataCamp
➔ R user ~7 years
➔ Enjoy talking about:
◆ Building and finding data
science community
◆ Diversity in STEM
◆ R
5. Life B.D. (Before DataCamp)
➔ Worked on 60+
experiments with search
team
➔ 8+ year history of
experimentation
➔ 500+ experiments per year
6. Life B.D. (Before DataCamp)
➔ 5 data engineers working on the experimentation platform
➔ Over a thousand metrics computed for each experiment
➔ Fancy UI
From How Etsy Handles Peeking in A/B Testing by Callie McRee and Kelly Shen
7. First weeks at DataCamp
➔ No system for planning,
analyzing, or presenting
experiment results
➔ And no data engineers to
build it
10. Who here has had a “first this then that” question?
➔ Who tried X then did Y?
➔ What percent of people who did X then did Y?
➔ What was the last thing people did before doing Y?
➔ What are all the things people did after doing X?
11. Questions I might answer about an A/B test
➔ What percent of people in the treatment vs. control registered?
➔ What were the ad clicks that had a course start within 2 days?
23. Things that have happened …
➔ People are put in both control and treatment
➔ People in the experiment have no page views
➔ People have multiple experiment starts in the same group
➔ There aren’t the same number of people in control and treatment
➔ Experiment starts didn’t have cookies (so we couldn’t track user)
32. Leveling up …
➔ Common request: What % increase can we detect in a 2 week test?
➔ Can I make a tool so people can answer this themselves without code?
➔ Delivering information -> discovering information
36. ➔ Clarifies decision-making
➔ Can have additional
“guardrail” metrics that you
don’t want to negatively
impact
Best Practice 1: Have one key metric per experiment
41. Recap
1. Build tools to save yourself time
2. Everything that can go wrong will go wrong
3. Build tools that empower others
4. Make it easy to do the right thing
42. Many thanks to …
➔ The growth and data science teams at DataCamp
➔ Anthony Baker & David Robinson, co-authors of funneljoin
➔ Analytics & Data Engineering team at Etsy