Slide 1

Slide 1 text

AB Testing Hector Zarate @ChocoChipset

Slide 2

Slide 2 text

AB Testing Hector Zarate @ChocoChipset

Slide 3

Slide 3 text

Hector Zarate (@ChocoChipset) Software Engineer at Spotify Boxun Zhang Data Scientist at Spotify

Slide 4

Slide 4 text

1. What?

Slide 5

Slide 5 text

No content

Slide 6

Slide 6 text

No content

Slide 7

Slide 7 text

YOU ARE PART OF AN EXPERIMENT

Slide 8

Slide 8 text

AB Testing

Slide 9

Slide 9 text

No content

Slide 10

Slide 10 text

Samson, 3

Slide 11

Slide 11 text

Max, 30 Samson, 3 +5% 
 matches

Slide 12

Slide 12 text

Share of Matches 20% 23.75% 27.5% 31.25% 35% Week 0 Week 1 Week 2 Week 3 Week 4 With Sunglasses Sunglasses

Slide 13

Slide 13 text

Share of Matches 20% 23.75% 27.5% 31.25% 35% Week 0 Week 1 Week 2 Week 3 Week 4 With Sunglasses Control Sunglasses

Slide 14

Slide 14 text

Share of Premium Conversion 20% 23.75% 27.5% 31.25% 35% Week 0 Week 1 Week 2 Week 3 Week 4 Variation A Control Sunglasses

Slide 15

Slide 15 text

User Retention 20% 23.75% 27.5% 31.25% 35% Week 0 Week 1 Week 2 Week 3 Week 4 Variation A Control Sunglasses

Slide 16

Slide 16 text

No content

Slide 17

Slide 17 text

spotify:user:chocochipset 92b2976bb15d26c9008

Slide 18

Slide 18 text

1 2 3 4 5 6 7 8 9 10 p ( x ) x 1 / n

Slide 19

Slide 19 text

1 2 3 4 5 6 7 8 9 10 p ( x ) x 1 / n

Slide 20

Slide 20 text

1 2 3 4 5 6 7 8 9 10 p ( x ) x 1 / n 0% 60%

Slide 21

Slide 21 text

Markets

Slide 22

Slide 22 text

Demographics

Slide 23

Slide 23 text

User Attributes

Slide 24

Slide 24 text

No content

Slide 25

Slide 25 text

Login resolveABFlags() response(ABFlags) ABBA Cache AB Values Load Cached or Default AB Flags

Slide 26

Slide 26 text

Example button.color = [UIColor spotifyGreen]; BOOL isButtonPink = ([abFlags[@“pink-buttons"] isEqual:@"1"]); if (isButtonPink) { // alternate path here: button.color = [UIColor spotifyPink]; } Key Value charts Enabled pink-buttons 0 buffer-quality low gallery-artist Control

Slide 27

Slide 27 text

Key Value charts Enabled pink-buttons 0 buffer-quality low gallery-artist Control Example button.color = [UIColor spotifyGreen]; BOOL isButtonPink = ([abFlags[@“pink-buttons"] isEqual:@"1"]); if (isButtonPink) { // alternate path here: button.color = [UIColor spotifyPink]; } Key Value charts Enabled pink-buttons 1 buffer-quality low gallery-artist Control pink-button 1 Variation A Control

Slide 28

Slide 28 text

Control Variation

Slide 29

Slide 29 text

Analytics impressions and interactions

Slide 30

Slide 30 text

* just a personal preference

Slide 31

Slide 31 text

2. How?

Slide 32

Slide 32 text

1. Hypothesis 2. Design 3. Run 4. Analysis

Slide 33

Slide 33 text

1. Formulate a Hypothesis

Slide 34

Slide 34 text

2. Design the Test

Slide 35

Slide 35 text

# shuffle plays 2.1 Target Metrics

Slide 36

Slide 36 text

# matches Samson, 3 # replies # walks in the park

Slide 37

Slide 37 text

2.2 Test Group more test bandwith, less confidence, smaller effect in business less test bandwith, more confidence, bigger effect in business Small Large

Slide 38

Slide 38 text

2.3 Duration

Slide 39

Slide 39 text

3. Run the test

Slide 40

Slide 40 text

1 2 3 4 5 6 7 8 9 10 p ( x ) x 1 / n Test A Test A Test B Test B Test A / Test B Watch out for conflicting tests!

Slide 41

Slide 41 text

Don’t cut them short! Bruno Cesar 48’ Ronaldo 89’ Morata 90’ + 4’ 2 -1

Slide 42

Slide 42 text

0 25 50 75 100 D1 D2 D3 D4 D5 D6 D7 D8 Don’t cut them short!

Slide 43

Slide 43 text

4. Analyze the results

Slide 44

Slide 44 text

1. Formulate 
 a Hypothesis new

Slide 45

Slide 45 text

3. Case Studies

Slide 46

Slide 46 text

3.1. Losing Calories

Slide 47

Slide 47 text

No content

Slide 48

Slide 48 text

No content

Slide 49

Slide 49 text

No content

Slide 50

Slide 50 text

No content

Slide 51

Slide 51 text

No content

Slide 52

Slide 52 text

No content

Slide 53

Slide 53 text

Test: Tab Bar Navigation Hypothesis: By switching to TBN, we expect an increase in the share of users who click at least one menu item. 1

Slide 54

Slide 54 text

Test: Tab Bar Navigation Hypothesis: By switching to TBN, we expect an increase in the share of users who click at least one menu item. 2.1

Slide 55

Slide 55 text

10% New Users 1% Existing Users 2.2

Slide 56

Slide 56 text

2.3 8 day period

Slide 57

Slide 57 text

4 Clicks on Menu Items 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 110% 120% 130% Control Tab Bar 130% 100%

Slide 58

Slide 58 text

4 Clicks Overall 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 110% 120% 130% Control Tab Bar 109% 100%

Slide 59

Slide 59 text

4 1. Increased clicks in Tab Items 2. Decreased clicks in non-tab items.

Slide 60

Slide 60 text

WHY AB TEST?
 QUANTIFY THE IMPACT OF A SPECIFIC CHANGE

Slide 61

Slide 61 text

3.2. Home in Mexico

Slide 62

Slide 62 text

My Rock Your Rock

Slide 63

Slide 63 text

My Home Your Home

Slide 64

Slide 64 text

My Home Your Home

Slide 65

Slide 65 text

Test: Home Hypothesis: We will measure an increased second week retention by using the new ‘Home’ as start page. 1

Slide 66

Slide 66 text

Test: Home Hypothesis: We will measure an increased second week retention by using the new ‘Home’ as start page. 2.1

Slide 67

Slide 67 text

US UK Germany Austria Mexico 4

Slide 68

Slide 68 text

1. Is the localization good? 2. Are recommendations relevant for the market? 3. Technical restrictions we are not aware of? 4

Slide 69

Slide 69 text

12.34 Mbps US 13.70 Mbps UK 13.42 Mbps Germany 15.48 Mbps Austria 7.4 Mbps Mexico * 3.7 Mb 4

Slide 70

Slide 70 text

1. Hypothesis 2. Design 3. Run 4. Analysis

Slide 71

Slide 71 text

Test: Home Hypothesis: By compressing the data sent for Home, more users will play on day one, two and be active during their second week. 1

Slide 72

Slide 72 text

4. Pitfalls

Slide 73

Slide 73 text

NO DATA

Slide 74

Slide 74 text

Max, 30 TOO MANY CHANGES

Slide 75

Slide 75 text

Max, WOLF AT WALL STREET TOO MANY CHANGES

Slide 76

Slide 76 text

DONT
 LISTEN TO YOUR HEART (LISTEN TO THE DATA)

Slide 77

Slide 77 text

5. Wrap Up

Slide 78

Slide 78 text

No content

Slide 79

Slide 79 text

No content

Slide 80

Slide 80 text

No content

Slide 81

Slide 81 text

No content

Slide 82

Slide 82 text

No content

Slide 83

Slide 83 text

KNOWLEDGE IS YOUR ROI

Slide 84

Slide 84 text

A test is an investment Design to maximize learning

Slide 85

Slide 85 text

NEGATIVE RESULTS ARE STILL POSITIVE

Slide 86

Slide 86 text

TRY AB TESTING

Slide 87

Slide 87 text

No content

Slide 88

Slide 88 text

Gracias! Hector Zarate @ChocoChipset spotify.com/jobs

Slide 89

Slide 89 text

Preguntas! Hector Zarate @ChocoChipset spotify.com/jobs