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The Subtle Art of Misleading
withStatistics
Dave McAllister
Sr. Open Source Technologist  NGINX
息2024 F5
2
TheSubtleArtofMisleading withStatistics
Open Source Technologist for NGINX
Owned by 3 cats
息2024 F5
3
Lies,DamnedLies,andStatistics
息2024 F5
4
 Evidence-Based Decisions
 PerformanceTracking
 Resource Allocation
 Identifying Patterns
 Setting Realistic Goals
ThePowerofStatistics
Its a data-driven world
It is the mark of a truly intelligent person to be moved by statistics. - George Bernard Shaw
 Data Interpretation and Decision-making
 PerformanceMetrics and KPIs
 Cultural Impact
 Risk Management
息2024 F5
5
 Misinterpretation
 Cherry-Picking Data
 Correlation vs. Causation
 Visualization
 Ignoring Margin of Error
 Spurious Precision
 Survivorship Bias
ButtheNumbersGame
isJustThat,aGame
Figures don't lie, but liars can figure. - Darrell Huff
息2024 F5
6
The Meaning of Averages
#1:SayWhatYouMean
Your KPI for downtime is 1 hour per month trailing.
Which one wouldyou rather report?
1.56 Hours/month or 0.53 Hours/month
It is now proved beyond doubt that smoking is one of
the leading causes of statistics.  Fletcher Knebel
息2024 F5
7
The Meaning of Averages
#1:SayWhatYouMean
Your KPI for downtime is 1 hour per month trailing.
Which one wouldyou rather report?
1.56 Hours/month or 0.53 Hours/month
 Current average income perperson in US = 59,384 USD
 Average household size in US = 2.63 people
 Household incomeobviously = $156,179.92
(Its not)
To earn a million dollars, you just need to have 14.8 kids, right?
It is now proved beyond doubt that smoking is one of
the leading causes of statistics.  Fletcher Knebel
息2024 F5
8
#2:NeverDeviate
 A statistical point without range is meaningless
The mean temperature is 61F/16.1C
In Death Valley, this is in a range of 15F - 104F
 A statistical distribution without expressing deviation is
worthless
Sample response times from server
 Sample A: [100ms, 105ms, 110ms, 102ms, 108ms]
 Sample B: [50ms, 100ms, 150ms, 90ms, 160ms]
Std Deviation A = 3.3ms
Std Deviation B = 44.8ms
In ancient times they had no statistics so they had to fall back on lies. 
Stephen Leacock
Normal Distribution
Paranormal Distribution
How Sample Size Affects Standard Error - dummies
息2024 F5
9
TANSTAAFS (with apologies to Robert Heinlein)
#3:SampleforYourDesiredResults
 Results are only as good as thesample data.
 But it can be really convincing
 Size matters (4 out of 5 SREs prefer OpenTofu)
 Bias is the hidden trap
 If you cant find the bias, look harder
If yousample only iPhone users, Androiddoesnt exist
 So is access
If yousample in a first class airline lounge, well
 Questions (and interviewers) can be their own bias
Accuracy of observation is the equivalent of accuracy of thinking. 
Wallace Stevens
息2024 F5
10
#4:DontFearProvingYourPredictions
 Cognitive bias
 Selection bias
 Recency bias
 Status Quo bias
If there have been no recent outages or incidents
 Perception that the system is very stable
 Complacency
 Inadequate preparation for potential failures
The type of measure used placed constraints on which statistics can be used.  Stanley Smith Stevens
息2024 F5
11
#5:DontSweattheBias
Youare trialing a new deployment tool for speed
and reliability
Yousample via survey the senior engineers who
were invited to try the new tool
1.
Do therespondents cover the entire group?
2. Confirmation Bias: Is the leading teamwording
questions to get skewed answers
3. Recency Bias: Is the last experience what is
being reported?
4. Status Quo Bias: Is change scary?
Definition of Statistics: The science of producing unreliable facts from reliable figures.  Evan Esar
Self-selection Bias:
息2024 F5
12
#5:DontSweattheBias
Youare trialing a new deployment tool for speed
and reliability
Q1: How happy are you with the new and improved
tool?
Q2: Would you agree that the new tool has
streamlined your deployment?
Q3: How beneficial has the new tool been?
1. Self-selection Bias: Do the respondents cover
the entire group?
2. Confirmation Bias:
Is thewording of questions leading to skewed
answers?
3. Recency Bias: Is the last experience what is
being reported?
4. Status QuoBias: Is change scary?
Definition of Statistics: The science of producing unreliable facts from reliable figures.  Evan Esar
Confirmation Bias:
息2024 F5
13
DevOpsSurveyandBias{Tape|Tires|Ply|Cut}
Youare trialing a new deployment tool for speed
and reliability
Q1: How happy are you with the new and improved
tool based on your most recent deployment?
Q2: How much did thetool help in your last
deployment?
Q3: Most recently, how beneficial has the new tool
been?
1. Self-selection Bias: Do the respondents cover
the entire group?
2. Confirmation Bias: Is the leading team wording
questions to get skewed answers
3. Recency Bias:
Is thelast experience what is being reported?
4. Status Quo Bias: Is change scary?
Definition of Statistics: The science of producing unreliable facts from reliable figures.  Evan Esar
Recency Bias:
息2024 F5
14
DevOpsSurveyandBias
Youare trialing a new deployment tool for speed
and reliability
Q1: How disruptive was the new tool?
Q2: Isthe existing process more reliable?
Q3: How much effort did you spend on using the
new tool?
1. Self-selection Bias: Do the respondents cover
the entire group?
2. Confirmation Bias: Is the leading team wording
questions to get skewed answers
3. Recency Bias: Is the last experience what is
being reported?
4. Status Quo Bias:
Is change scary?
Definition of Statistics: The science of producing unreliable facts from reliable figures.  Evan Esar
Status Quo Bias:
息2024 F5
15
#6:APictureisWorthaThousandMisleads
Beware of misleading visual representations, such as manipulated graphs  Darrell Huff
息2024 F5
16
APictureisWorthaThousandLies
0
90
Statistics are used a lot like a drunk uses a lamppost: for support, not illumination  Vin Scully
0 %
100 %
息2024 F5
17
APictureisWorthaThousandLies
0
90
Statistics are used a lot like a drunk uses a lamppost: for support, not illumination  Vin Scully
0 %
100 %
息2024 F5
18
APictureisWorthaThousandLies
0
90
Statistics are used a lot like a drunk uses a lamppost: for support, not illumination  Vin Scully
息2024 F5
19
#7:StronglySuggesttheAnswer
CY2022 CY2023 CY2024
60
70
80
There are two kinds of statistics, the kind you look up and the kind you make up  Rex Stout
息2024 F5
20
ThePowerofSuggestionOneDimensionalPicture
CY2022 CY2023 CY2024
60
70
80
You can shape statistics to make them look however you want them to.  Jamie Carragher
息2024 F5
21
#7:AssumeNoOneReadstheFinePrint
Adventures
In
Misleading
Graphs
~
Crazy
Test
Blog
There are 50 million Wii owners. 6% of that number is 3 million.
There are 30 million 360 owners. 11% of that number is 3.3 million.
There are 20 million PS3 owners. 10% of that number is 2 million.
82%
85%
63%
H/T Lee Evans
230% ??
息2024 F5
22
#8:ObviouslyIfBFollowsA,thenACausesB
Those who use 'Correlation is not the same as causation' as a magic incantation to dismiss all fact-using professions are
fools holding a lit match in one hand and an open gas can in the other, screaming, 'One has nothing to do with the other!'
You want to prove you have too much automation.
Your DevOps team notices that as the number of
deployment automation scripts increases, the
number of incidents in production increases.
息2024 F5
23
UsuallyStatedas
CorrelationisNotCausation
 Confounding Variable
 Reverse Causation
 Coincidence
 Bidirectional Causation
 Sampling Bias
 Measurement Errors
Correlation
Causation
息2024 F5
24
Myfavoritesneakycorrelation
Does drinking cause marriage?
or
does marriage cause drinking?
息2024 F5
25
Data Dredging and p-hacking
#9:Find(orMake)thedatayouwant
Data dredging
 The practice of searching through large volumes of data to find
patterns or relationships that can be presented as statistically
significant
P-hacking
 Manipulating the data analysis process to achieve statistically
significant results.
Instead of starting with a hypothesis and testing it, I instead abused the data to see what correlations shake out. Its a dangerous way to
go about analysis, because any sufficiently large dataset will yield strong correlations completely at random.  Tyler Vigen
息2024 F5
26
Doublethefun.
Cherry picked block of years showing that global warming is fake.
息2024 F5
27
Eighty-two percent of the country understands that
it was a rigged election,
March 2nd, 2024
息2024 F5
28
Initial source : Public Religion Research Institute.
Publish date 01-Nov-2021
(they did a good job,btw)
Total Sample : 2508
People trusting far-right sources completely: 90
People trusting Fox News completely: ~66
So at 82%, 54 people out of 66 believe
Or 54 out of 2508
2.15%
#10:PostHoc,ErgoPropterHoc
Afterthis,thereforebecauseofthis
息2024 F5
29
The answer is pointless without the question>
What do you get if you multiply 6 X 9?
Which of course is 4213
息2024 F5
30
Statistics are informative, enlightening and pretty cool.
But always apply the ultimate test:Does this make sense?
Look out for:
 Conscious and Unconscious bias
 Data Dredging
 Unclear or incomplete information
 Confounding variables
 Pretty pictures
ASimpleWaytoMislead?
Numbers dont lie. People do.  Hugh Baker
息2024 F5
31
Questions?
https://www.linkedin.com/in/davemc
https://www.github.com/dwmcallister
Statistics are history.
And history is written by the winners.
 Dave McAllister
息2024 F5
32
Somesuggestedreading
Statistics for the Rest of Us  Albert Rutherford
How to Lie with Statistics  DarrellHuff
LyingNumbers  Hugh Barker
Naked Statistics  Charles Wheelan
Statistics for Dummies  Deborah J Rumsey
Standard Deviations: Flawed Assumptions, Tortured Data, and Other
Ways to Lie with Statistics  Gary Smith
Misleading Statistics  Real Life Examples Of Data Misuse (datapine.com)
Spurious Correlations (tylervigen.com)
A History of Bayes' Theorem
Statistics are history. And history is always written by the winners.
 Dave McAllister
息2024 F5
33
NGINXandOpenSource
 We will continue to offer our open source projects under OSI-
approved licenses
 We will not remove features from our open source
technology to move them to a paid feature
 We will not impose artificial limits on the use of our open
source projects
 We will commit to consistency and transparency in our
acceptance of contributions
OSMC 2024 | The Subtle Art of Lying with Statistics Dave McAllister.pdf

More Related Content

OSMC 2024 | The Subtle Art of Lying with Statistics Dave McAllister.pdf

  • 1. The Subtle Art of Misleading withStatistics Dave McAllister Sr. Open Source Technologist NGINX
  • 2. 息2024 F5 2 TheSubtleArtofMisleading withStatistics Open Source Technologist for NGINX Owned by 3 cats
  • 4. 息2024 F5 4 Evidence-Based Decisions PerformanceTracking Resource Allocation Identifying Patterns Setting Realistic Goals ThePowerofStatistics Its a data-driven world It is the mark of a truly intelligent person to be moved by statistics. - George Bernard Shaw Data Interpretation and Decision-making PerformanceMetrics and KPIs Cultural Impact Risk Management
  • 5. 息2024 F5 5 Misinterpretation Cherry-Picking Data Correlation vs. Causation Visualization Ignoring Margin of Error Spurious Precision Survivorship Bias ButtheNumbersGame isJustThat,aGame Figures don't lie, but liars can figure. - Darrell Huff
  • 6. 息2024 F5 6 The Meaning of Averages #1:SayWhatYouMean Your KPI for downtime is 1 hour per month trailing. Which one wouldyou rather report? 1.56 Hours/month or 0.53 Hours/month It is now proved beyond doubt that smoking is one of the leading causes of statistics. Fletcher Knebel
  • 7. 息2024 F5 7 The Meaning of Averages #1:SayWhatYouMean Your KPI for downtime is 1 hour per month trailing. Which one wouldyou rather report? 1.56 Hours/month or 0.53 Hours/month Current average income perperson in US = 59,384 USD Average household size in US = 2.63 people Household incomeobviously = $156,179.92 (Its not) To earn a million dollars, you just need to have 14.8 kids, right? It is now proved beyond doubt that smoking is one of the leading causes of statistics. Fletcher Knebel
  • 8. 息2024 F5 8 #2:NeverDeviate A statistical point without range is meaningless The mean temperature is 61F/16.1C In Death Valley, this is in a range of 15F - 104F A statistical distribution without expressing deviation is worthless Sample response times from server Sample A: [100ms, 105ms, 110ms, 102ms, 108ms] Sample B: [50ms, 100ms, 150ms, 90ms, 160ms] Std Deviation A = 3.3ms Std Deviation B = 44.8ms In ancient times they had no statistics so they had to fall back on lies. Stephen Leacock Normal Distribution Paranormal Distribution How Sample Size Affects Standard Error - dummies
  • 9. 息2024 F5 9 TANSTAAFS (with apologies to Robert Heinlein) #3:SampleforYourDesiredResults Results are only as good as thesample data. But it can be really convincing Size matters (4 out of 5 SREs prefer OpenTofu) Bias is the hidden trap If you cant find the bias, look harder If yousample only iPhone users, Androiddoesnt exist So is access If yousample in a first class airline lounge, well Questions (and interviewers) can be their own bias Accuracy of observation is the equivalent of accuracy of thinking. Wallace Stevens
  • 10. 息2024 F5 10 #4:DontFearProvingYourPredictions Cognitive bias Selection bias Recency bias Status Quo bias If there have been no recent outages or incidents Perception that the system is very stable Complacency Inadequate preparation for potential failures The type of measure used placed constraints on which statistics can be used. Stanley Smith Stevens
  • 11. 息2024 F5 11 #5:DontSweattheBias Youare trialing a new deployment tool for speed and reliability Yousample via survey the senior engineers who were invited to try the new tool 1. Do therespondents cover the entire group? 2. Confirmation Bias: Is the leading teamwording questions to get skewed answers 3. Recency Bias: Is the last experience what is being reported? 4. Status Quo Bias: Is change scary? Definition of Statistics: The science of producing unreliable facts from reliable figures. Evan Esar Self-selection Bias:
  • 12. 息2024 F5 12 #5:DontSweattheBias Youare trialing a new deployment tool for speed and reliability Q1: How happy are you with the new and improved tool? Q2: Would you agree that the new tool has streamlined your deployment? Q3: How beneficial has the new tool been? 1. Self-selection Bias: Do the respondents cover the entire group? 2. Confirmation Bias: Is thewording of questions leading to skewed answers? 3. Recency Bias: Is the last experience what is being reported? 4. Status QuoBias: Is change scary? Definition of Statistics: The science of producing unreliable facts from reliable figures. Evan Esar Confirmation Bias:
  • 13. 息2024 F5 13 DevOpsSurveyandBias{Tape|Tires|Ply|Cut} Youare trialing a new deployment tool for speed and reliability Q1: How happy are you with the new and improved tool based on your most recent deployment? Q2: How much did thetool help in your last deployment? Q3: Most recently, how beneficial has the new tool been? 1. Self-selection Bias: Do the respondents cover the entire group? 2. Confirmation Bias: Is the leading team wording questions to get skewed answers 3. Recency Bias: Is thelast experience what is being reported? 4. Status Quo Bias: Is change scary? Definition of Statistics: The science of producing unreliable facts from reliable figures. Evan Esar Recency Bias:
  • 14. 息2024 F5 14 DevOpsSurveyandBias Youare trialing a new deployment tool for speed and reliability Q1: How disruptive was the new tool? Q2: Isthe existing process more reliable? Q3: How much effort did you spend on using the new tool? 1. Self-selection Bias: Do the respondents cover the entire group? 2. Confirmation Bias: Is the leading team wording questions to get skewed answers 3. Recency Bias: Is the last experience what is being reported? 4. Status Quo Bias: Is change scary? Definition of Statistics: The science of producing unreliable facts from reliable figures. Evan Esar Status Quo Bias:
  • 15. 息2024 F5 15 #6:APictureisWorthaThousandMisleads Beware of misleading visual representations, such as manipulated graphs Darrell Huff
  • 16. 息2024 F5 16 APictureisWorthaThousandLies 0 90 Statistics are used a lot like a drunk uses a lamppost: for support, not illumination Vin Scully 0 % 100 %
  • 17. 息2024 F5 17 APictureisWorthaThousandLies 0 90 Statistics are used a lot like a drunk uses a lamppost: for support, not illumination Vin Scully 0 % 100 %
  • 18. 息2024 F5 18 APictureisWorthaThousandLies 0 90 Statistics are used a lot like a drunk uses a lamppost: for support, not illumination Vin Scully
  • 19. 息2024 F5 19 #7:StronglySuggesttheAnswer CY2022 CY2023 CY2024 60 70 80 There are two kinds of statistics, the kind you look up and the kind you make up Rex Stout
  • 20. 息2024 F5 20 ThePowerofSuggestionOneDimensionalPicture CY2022 CY2023 CY2024 60 70 80 You can shape statistics to make them look however you want them to. Jamie Carragher
  • 21. 息2024 F5 21 #7:AssumeNoOneReadstheFinePrint Adventures In Misleading Graphs ~ Crazy Test Blog There are 50 million Wii owners. 6% of that number is 3 million. There are 30 million 360 owners. 11% of that number is 3.3 million. There are 20 million PS3 owners. 10% of that number is 2 million. 82% 85% 63% H/T Lee Evans 230% ??
  • 22. 息2024 F5 22 #8:ObviouslyIfBFollowsA,thenACausesB Those who use 'Correlation is not the same as causation' as a magic incantation to dismiss all fact-using professions are fools holding a lit match in one hand and an open gas can in the other, screaming, 'One has nothing to do with the other!' You want to prove you have too much automation. Your DevOps team notices that as the number of deployment automation scripts increases, the number of incidents in production increases.
  • 23. 息2024 F5 23 UsuallyStatedas CorrelationisNotCausation Confounding Variable Reverse Causation Coincidence Bidirectional Causation Sampling Bias Measurement Errors Correlation Causation
  • 24. 息2024 F5 24 Myfavoritesneakycorrelation Does drinking cause marriage? or does marriage cause drinking?
  • 25. 息2024 F5 25 Data Dredging and p-hacking #9:Find(orMake)thedatayouwant Data dredging The practice of searching through large volumes of data to find patterns or relationships that can be presented as statistically significant P-hacking Manipulating the data analysis process to achieve statistically significant results. Instead of starting with a hypothesis and testing it, I instead abused the data to see what correlations shake out. Its a dangerous way to go about analysis, because any sufficiently large dataset will yield strong correlations completely at random. Tyler Vigen
  • 26. 息2024 F5 26 Doublethefun. Cherry picked block of years showing that global warming is fake.
  • 27. 息2024 F5 27 Eighty-two percent of the country understands that it was a rigged election, March 2nd, 2024
  • 28. 息2024 F5 28 Initial source : Public Religion Research Institute. Publish date 01-Nov-2021 (they did a good job,btw) Total Sample : 2508 People trusting far-right sources completely: 90 People trusting Fox News completely: ~66 So at 82%, 54 people out of 66 believe Or 54 out of 2508 2.15% #10:PostHoc,ErgoPropterHoc Afterthis,thereforebecauseofthis
  • 29. 息2024 F5 29 The answer is pointless without the question> What do you get if you multiply 6 X 9? Which of course is 4213
  • 30. 息2024 F5 30 Statistics are informative, enlightening and pretty cool. But always apply the ultimate test:Does this make sense? Look out for: Conscious and Unconscious bias Data Dredging Unclear or incomplete information Confounding variables Pretty pictures ASimpleWaytoMislead? Numbers dont lie. People do. Hugh Baker
  • 32. 息2024 F5 32 Somesuggestedreading Statistics for the Rest of Us Albert Rutherford How to Lie with Statistics DarrellHuff LyingNumbers Hugh Barker Naked Statistics Charles Wheelan Statistics for Dummies Deborah J Rumsey Standard Deviations: Flawed Assumptions, Tortured Data, and Other Ways to Lie with Statistics Gary Smith Misleading Statistics Real Life Examples Of Data Misuse (datapine.com) Spurious Correlations (tylervigen.com) A History of Bayes' Theorem Statistics are history. And history is always written by the winners. Dave McAllister
  • 33. 息2024 F5 33 NGINXandOpenSource We will continue to offer our open source projects under OSI- approved licenses We will not remove features from our open source technology to move them to a paid feature We will not impose artificial limits on the use of our open source projects We will commit to consistency and transparency in our acceptance of contributions