What are the common assumptions about AB (split) testing that are wrong? What are the lies told by vendors, consultants and the stuff you have convinced yourself about. What is illusory - what can you trust - what's it really all about. 20 top myths debunked after asking fellow CRO professionals what is on THEIR top list.

1. Myths,
Lies and
Illusions
of Split
Testing
@OptimiseOrDie

2. @OptimiseOrDie
• UX, Analytics, Split Testing and Growth Rate Optimisation
• Started doing testing & CRO 2004
• Split tested over 45M visitors in 19 languages
• 67+ mistakes I MADE with AB testing
• Like riding a bike…
• Optimise your optimisation? Get in touch!

4. Myths, Lies and Illusions of Optimisation
1. Optimisation and Testing are the same
2. Optimisation and Testing are easy
3. Statistical significance tells you when to stop
4. High traffic always makes tests shorter
5. It’s all about Conversion Rates
6. You don’t need to test the test
7. Your tests will give you the quoted lift
8. High traffic pages give the best tests
9. It’s about getting all your tests to win
10. Optimisation is only about websites
@OptimiseOrDie
11. Segmentation will tell you what happened
12. You can’t run multiple simultaneous tests
13. Testing is great for settling arguments
14. You can spot trends early on in a test
15. More test volumes = better results
16. Your tests tell you truths that last forever
17. You can test even on low traffic sites
18. Other people’s tests are ‘Best Practice’
19. Doesn’t involve changing the way you work
20. Testing makes you a Data Scientist

5. #fail
@OptimiseOrDie

6. @OptimiseOrDie
26.6M

7. @OptimiseOrDie28.4M

8. Oppan Gangnam Style!
@OptimiseOrDie6.9M

9. You naughty boy…

10. @OptimiseOrDie1. Testing & Optimisation are the same thing
Testin
g
Optimise

11. What is CRO/Optimisation?
• “Using Analytics data and
Customer feedback to improve the
performance of your website.”
• “Finding out why visitors aren’t
converting and then resolving
these issues.”
• “Running loads of crappy split tests
randomly until the heat death of
the universe”
@OptimiseOrDie

12. What is my definition?
“A structured, systematic and continuous
application of techniques that are used to
discover, quantify and prioritise issues.
These can be turned into hypotheses to drive
experiments and opportunity in the following
business outcomes:”
• Increased revenue or profitability
• Increasing LTV, loyalty, NPS/Sat scores, Kristoffer Potential
• Removing cost from the business or contact center
• Higher productivity or labour flexibility
• Delighting customers
• Reduced development effort
@OptimiseOrDie

13. What Optimisation is NOT!
• A way to change things you (or others) hate
• A methodology for running split tests
• A guarantee of increased conversion
• A methodology for looking at analytics data
• A rescue for silo-bound or non-agile design or
development processes
• A way to trick people into buying
• A bolt-on – it IS the process
@OptimiseOrDie

14. Optimisation is a:
• Way of joining the worlds of Customer insight, UX,
Analytics, Split testing and Business Strategy
• Overarching Design and development process which
prioritises work around opportunity
• Strategic, not tactical, response to wasted development
effort or product change
• Way to create a deep and meaningful connection
between the team, customers, business and the outcomes
of making product changes
• The killer app to remove ego, opinion, assumptions,
cherished notions or ‘we just do it that way’ from decision
making.
• More powerful method than UX research or analytics
alone, in guiding the directionality of product change
@OptimiseOrDie

15. Optimisation includes these:
• Qualitative research
• Analytics, Quant analysis and
insight
• UX inspection and discovery
• Competitive Intelligence
• Priority based opportunity
• VOC, Surveys and Customer
Satisfaction (NPS)
• Call tracking & Call centre
optimisation
• AB testing
• Multivariate testing
• Photography optimisation
• EEG / ECG / Galvanic response
@OptimiseOrDie
• Web performance tuning
• Forms analytics
• Eye tracking
• Market research
• Big & Unstructured data analysis
• PPC optimisation
• Session replay analysis
• Customer journey mapping
• Ethnographic (diary) study
research
• Cross device, platform and
channel insight
• Email optimisation

16. 2. Optimisation & Testing are
EASY

17. Surely you just add Javascript?
• This work is harder than anything I’ve ever done!
• You all have expensive & limited resources for testing - like Airport take-off slots
• You MUST make use of these efficiently
• You HAVE to balance resource cost with opportunity by prioritising carefully
@OptimiseOrDie
• You’re doing the equivalent of drug trials!
• For large OR small companies, the instrumentation, analytics, tools
setup, plan design, test methodology and analysis cannot be ‘done
later on’. It’s not complex but it is vital.
• The best companies have a structural shell (process, methodology,
management) around their activities
• If you’re not optimising the process continuously (Kaizen), you won’t
increase your velocity of iterations.
• Optimise the Optimisation

18. 3. Statistical significance tells you when to
stop
@OptimiseOrDie

19. The 95% Stopping Problem
@OptimiseOrDie
• Many people use 95, 99% ‘confidence’ to stop
• This value is unreliable and moves around
• Nearly all my tests reach significance before they are
actually ready
• You can hit 95% early in a test (18 minutes!)
• If you stop, it could be a false result
• Read this Nature article : bit.ly/1dwk0if
• Optimizely have changed their stats engine
• This 95% thingy – must be LAST on your stop list
• Let me explain

20. The 95% Stopping Problem
@OptimiseOrDie
Scenario 1 Scenario 2 Scenario 3 Scenario 4
After 200
observations
Insignificant Insignificant Significant! Significant!
After 500
observations
Insignificant Significant! Insignificant Significant!
End of
experiment
Insignificant Significant! Insignificant Significant!
“You should know that stopping a test once it’s significant is deadly sin
number 1 in A/B testing land. 77% of A/A tests (testing the same thing
as A and B) will reach significance at a certain point.”
Ton Wesseling, Online Dialogue

21. The 95% Stopping Problem
@OptimiseOrDie
“Statistical Significance does not equal Validity”
http://bit.ly/1wMfmY2
“Why every Internet Marketer should be a Statistician”
http://bit.ly/1wMfs1G
“Understanding the Cycles in your site”
http://mklnd.com/1pGSOUP

22. 4. High Traffic always means short tests
@OptimiseOrDie

23. Business & Purchase Cycles
@OptimiseOrDie
• Customers change
• Your traffic mix changes
• Markets, competitors
• Be aware of all the waves
• Always test whole cycles
• Don’t exclude slower buyers
• When you stop, let test
subjects still complete!
Start Test Finish Avg Cycle

24. • TWO BUSINESS CYCLES minimum (week/mo)
• 1 PURCHASE CYCLE minimum
• 250 CONVERSIONS minimum per creative (e.g. checkouts)
• 350 & MORE! if response is very similar
• FULL WEEKS/CYCLES never part of one
• KNOW what marketing, competitors and cycles are doing
• RUN a test length calculator - bit.ly/XqCxuu
• SET your test run time , RUN IT, STOP IT, ANALYSE IT
• ONLY RUN LONGER if you need more data
• DON’T RUN LONGER just because the test isn’t giving the result you want!
@OptimiseOrDie
How Long? Simple Rules to follow

25. 5. It’s ALL about Conversion Rate
@OptimiseOrDie

26. It’s all about the business
@OptimiseOrDie
• You’re optimising a business here, not a page or site
• Tricking, pushing or persuading people at a superficial level to
take an action is not a viable strategy
• Your optimisation strategy is a series of steps, not a tool
• Testing is about learning, not converting.
• Tests that fail to tell you anything (regardless of outcome) are
a failure themselves
• If you don’t shift the business goals, your optimisation and
testing budget will be threatened

27. 6. You don’t need to test the test – just
go
@OptimiseOrDie
Browser testing www.crossbrowsertesting.com
www.browserstack.com
www.spoon.net
www.saucelabs.com
www.multibrowserviewer.com
Mobile devices www.appthwack.com
www.deviceanywhere.com
www.opendevicelab.com
Read this article bit.ly/1wBccsJ

28. 7. The test result gives the promised lift
@OptimiseOrDie

29. The result is a range
@OptimiseOrDie
• Version A is 3% conversion
• Version B is 4% conversion
• Yay! That’s a 25% lift
• Let’s tell everyone
• When it goes live, you get 5.7%
• That’s because it was A RANGE
• 3% +/- 0.5
• 4% +/- 0.4
• Actual result was 3.5% for A
• Actual result was 3.7% for B

30. AB Testing Visualisation Tool
@OptimiseOrDie
abtestguide.com/calc/

31. 8. Testing is best on high traffic pages
@OptimiseOrDie
Think like the CEO of a
department store!
If you can’t refurbish the entire
store, which floors or
departments will you invest in
optimising?
Wherever there is:
• Footfall
• Low return
• Opportunity

32. Ecommerce
Bounce
Search or
Category
Product
Page
Add to
basket
View
basket
Checkout
Complete
@OptimiseOrDie
8. Testing is best on high traffic pages

33. @OptimiseOrDie
8. It’s all about prioritisation!

34. 9. It’s all about WINNING test results
@OptimiseOrDie

35. Failing is good
@OptimiseOrDie
• Tests that are ‘about the same’ are a failure
• They’re also very hard to call
• That means you have to be BOLD not conservative
• A test that comes out negative is NOT a failure
• If a ‘negative’ test teaches you something, it’s a success!
• If you hit 40/50/60% failed tests, that’s fine
• If you aren’t failing regularly, you’re not BOLD enough
• Success is about the number of tests you finish each month,
and what you learn from them

36. We believe that doing [A]
for People [B] will make
outcome [C] happen.
We’ll know this when we
observe data [D] and
obtain feedback [E].
(reverse)
@OptimiseOrDie

37. 10. Optimisation is only for Websites
@OptimiseOrDie

38. Optimisation is just for
websites
@OptimiseOrDie
• Service Design (Airbnb)
• Onboarding flows with emails
• Email templates
• Apps – testing, debugging, tracking
• Phone tracking and call centre optimisation
• Social, Display, TV, Video and other advertising
• Print adverts, Direct Mail
• In-store promotions
• Product manuals, guides, interfaces
• EVERYTHING has elasticity – just find it
• Even Multi-variate call centre scripts

39. 11. Segmentation will explain things
@OptimiseOrDie

40. Segmentation explains stuff
@OptimiseOrDie
• Beware of small sample sizes
• A = 350 conversions
• B = 300 conversions
• A Conversions for Safari = 20
• B Conversions for Safari = 25
• Only needs 2 people to change that from 25% lift to 14%

41. 12. You can’t run concurrent split tests
@OptimiseOrDie

42. Oh yes you can, with GA!
@OptimiseOrDie
• If you push events or variables into GA, you can report on
behaviour for A or B (or any variations).
• If you do it that way, you can easily run multiple tests on
different page targets simultaneously.
• You grab AAA, AAB, ABA, ABB and analyse.
• Test subjects get a recipe of tests, so one caveat
• If you pick things that clash or jar the experience
• If you have $5 delivery but then $2 in another test
• Apart from that, it’s fine to run these
• They tell you about the right experience recipe across several
pages being optimised in concert

43. 13. Testing is great for settling arguments
@OptimiseOrDie

44. 14. You can spot trends early in a test
@OptimiseOrDie

45. You can spot trends early
@OptimiseOrDie
• Tests are volatile in the early stages
• Watch but shut your mouth and wait
• Keep an eye on any odd behaviour
• Be patient!

46. 15. More tests = Better results
@OptimiseOrDie

47. More tests = Better results
@OptimiseOrDie
• Increasing volume without optimising velocity
• Not optimising the process means it scales badly
• If you put garbage in, you’ll get garbage out
• Ramping up before you have it tuned is crazy
• Get the team, process, project management, methodology,
toolkits, selling and PR nailed first
• THEN optimise and scale
• I know that one UK retailer is doing 140 per month!
• That’s LOW compared to some companies I work with
• Big companies doing 2 a month? Meh.

48. 16. Each test is a truth FOREVER
@OptimiseOrDie

49. Tests are a Truth Forever
@OptimiseOrDie
• Traffic changes
• Prices change
• Product mix changes
• Advertising evolves and changes
• Markets are different
• Customers have changed
• Competitors or regulatory landscape moves
• Things happen outside of your control
• You need to revisit tests or ITERATE
• Always be trying to beat the new winner, not basking in the
glory of a test you ran 9 months ago
• The lift may have vanished
• Schrodinger’s AB test

50. 17. Testing is fine on Low Traffic sites
@OptimiseOrDie

51. Testing is fine on low traffic
sites
@OptimiseOrDie
• Yes, if you estimate your minimum testing unit
• This is the time to AB test a sample of say 250 conversions, with
the rules I set earlier.
• A payday loan company? 2 months minimum!
• Run the calculations
• Check the test length
• If it takes like, 8 million years, what can you do?
• Read this or download my AB testing decks:
bit.ly/1umy5Y6

52. 18. Other people’s tests are Best Practice
@OptimiseOrDie
“STOP copying your competitors
They may not know what the
f*** they are doing either”
Peep Laja, ConversionXL

53. Tests you see online?
@OptimiseOrDie
• Your customers are not the same
• Your site is not the same
• Your advertising and traffic is not the same
• Your UX is not the same
• How the f*** do you think it guarantees a result?
• Use them to inform or suggest ideas
• They’re like the picture on meal packets
• Serving Suggestion Only

54. 19. Testing makes you a Data Scientist
@OptimiseOrDie

55. 20. Testing and Innovation is a plugin
@OptimiseOrDie

56. WE’RE ALL WINGING
IT

57. Guessaholics Anonymous

58. 2004 Headspace
What I thought
I knew in 2004
Reality

59. 2014 Headspace
What I
KNOW
I know
Me, on a
good day

60. Rumsfeldian
Space

61. @OptimiseOrDie
#1 Culture & Team
#2 Toolkit & Analytics investment
#3 UX, CX, Service Design, Insight
#4 Persuasive Copywriting
#5 Experimentation (testing) tools
The 5 Legged Optimisation
Barstool

62. @OptimiseOrDie
Marketing
?
Variation
Heritability
of good
ideas
Selection
based on
death

63. Business Future Testing?
Congratulations!
Today you’re the lucky
winner of our random
awards programme.
You get all these extra
features for free, on us.
Enjoy.
Mr D. Vader

64. Thank You!
Mail : sullivac@gmail.com
Deck :
Linkedin : linkd.in/pvrg14

65. READ STUFF

66. READ STUFF

67. READ STUFF

68. #5 : FIND STUFF
@OptimiseOrDie
@danbarker Analytics
@fastbloke Analytics
@timlb Analytics
@jamesgurd Analytics
@therustybear Analytics
@carmenmardiros Analytics
@davechaffey Analytics
@priteshpatel9 Analytics
@cutroni Analytics
@avinash Analytics
@Aschottmuller Analytics, CRO
@cartmetrix Analytics,
CRO
@Kissmetrics CRO / UX
@Unbounce CRO / UX
@Morys CRO / Neuro
@UXFeeds UX / Neuro
@Psyblog Neuro
@Gfiorelli1 SEO / Analytics
@PeepLaja CRO
@TheGrok CRO
@UIE UX
@LukeW UX / Forms
@cjforms UX / Forms
@axbom UX
@iatv UX
@Chudders Photo UX
@JeffreyGroks Innovation
@StephanieRieger Innovation
@BrianSolis Innovation
@DrEscotet Neuro
@TheBrainLady Neuro
@RogerDooley Neuro
@Cugelman Neuro
@Smashingmag Dev / UX
@uxmag UX
@Webtrends UX /
CRO

69. #5 : LEARN STUFF
@OptimiseOrDie
Baymard.com
Lukew.com
Smashingmagazine.com
ConversionXL.com
Medium.com
Whichtestwon.com
Unbounce.com
Measuringusability.com
RogerDooley.com
Kissmetrics.com
Uxmatters.com
Smartinsights.com
Econsultancy.com
Cutroni.com
www.GetMentalNotes.com

70. #12 : The Best Companies…
• Invest continually in analytics instrumentation, tools, people
• Use an Agile, iterative, cross-silo, one team project culture
• Prefer collaborative tools to having lots of meetings
• Prioritise development based on numbers and insight
• Practice real continuous product improvement, not SLEDD*
• Are fixing bugs, cruft, bad stuff as well as optimising
• Source photos and content that support persuasion and utility
• Have cross channel, cross device design, testing and QA
• Segment their data for valuable insights, every test or change
• Continually reduce cycle (iteration) time in their process
• Blend ‘long’ design, continuous improvement AND split tests
• Make optimisation the engine of change, not the slave of ego
* Single Large Expensive Doomed Developments

71. THE FUTURE OF TESTING :
www.conductrics.com