This is How Easy It Is to Lie With Statistics

Zach Star
4 Feb 201918:54

Summary

TLDRThis video explores the power and potential misuse of statistics in various scenarios, from marketing strategies like Target's pregnancy prediction algorithm to courtroom cases like the Sally Clark trial. It highlights how statistics can be manipulated or misrepresented, leading to significant consequences in advertising, legal judgments, and public perception.

Takeaways

  • 🤰 Target's data analysis identified pregnant customers by analyzing their shopping patterns, leading to targeted marketing strategies.
  • 🔍 Statistician Andrew Pole developed an algorithm to predict customers' pregnancy status and due dates, enhancing Target's marketing effectiveness.
  • 🤔 Target's approach to sending coupons for baby products was subtle to avoid alarming customers, blending them with unrelated items.
  • 😡 A father's initial anger over receiving baby-related coupons turned to embarrassment when he discovered his daughter was indeed pregnant, highlighting the predictive power of Target's algorithm.
  • 👵 In a 1964 case, statistics were used in court to calculate the probability of an innocent couple matching witness descriptions, leading to a guilty verdict.
  • 👶 The Sally Clark case demonstrated the misuse of statistics in a criminal trial, where the probability of two infants dying from SIDS was misinterpreted, resulting in a wrongful conviction.
  • 📊 Misleading statistics can be created by omitting zero as a baseline in graphs, exaggerating differences and potentially influencing public opinion.
  • 📈 The UK's advertising standards authority criticized Colgate's claim that '80% of dentists recommend Colgate' due to the misleading nature of the statement.
  • 🤔 The difference between a 100% increase in a small number and a small percentage increase can be misleading, as shown in the high school dropout rate example.
  • 🔗 Correlation does not necessarily imply causation, as seen in the examples of head lice and health, or ice cream sales and heat strokes.
  • 📚 The Simpson's paradox illustrates how data can be misleading when not properly grouped, as seen in the Berkeley graduate school acceptance rates.

Q & A

  • What was the main challenge that Target presented to statistician Andrew Pole in 2002?

    -The challenge was to develop an algorithm using only computers to determine which customers were pregnant, even if they didn't want Target to know, by analyzing their shopping patterns.

  • What common shopping behaviors did Andrew Pole identify among expectant mothers?

    -Andrew Pole noticed behaviors such as an increase in lotion purchases, loading up on vitamins, and buying other pregnancy-related items, which he used to determine the likelihood of customers being pregnant.

  • How did Target use the information from the algorithm to benefit their marketing strategy?

    -Target used the information to send coupons to customers at the right time, corresponding to their pregnancy stages and due dates, even after the baby was born, to enhance their marketing effectiveness.

  • Why did Target mix pregnancy-related coupons with unrelated products?

    -Target mixed these coupons to avoid alarming customers who might not have disclosed their pregnancy, making the coupons seem more natural and less intrusive.

  • What incident led to the revelation of Target's pregnancy prediction algorithm?

    -A man from Minnesota was upset because Target was sending his high school daughter coupons for baby-related items. Later, he realized that the algorithm had correctly predicted his daughter's pregnancy before he knew about it.

  • Can you explain the famous case of Janet Collins and her husband Malcolm involving the use of statistics in the courtroom?

    -Janet Collins and Malcolm were accused of a crime based on witness descriptions. A mathematician calculated the probability of an innocent couple matching all the descriptions, concluding it was less than 1 in 12 million, which influenced the jury to find them guilty.

  • What is the issue with the claim '80% of dentists recommend Colgate' as used in a 2007 UK advertisement?

    -The issue is that the study allowed dentists to recommend more than one toothpaste brand, so while 80% recommended Colgate, it was also true that 100% recommended other brands like Crest, which could mislead consumers.

  • How can a 100% increase sometimes be misleading when describing changes in percentages?

    -A 100% increase can be misleading if the initial percentage is very small, as it might represent only a tiny absolute change. For example, going from 0.0001% to 0.0002% is a 100% increase but represents a very small actual change.

  • What is the difference between correlation and causation in statistics?

    -Correlation indicates a statistical relationship between two variables, while causation implies that one variable causes the other. Just because two things are correlated does not mean one causes the other; they could be caused by a third factor or simply occur together by chance.

  • Can you provide an example of the misuse of statistics in a legal case?

    -The case of Sally Clark is an example where the misuse of statistics led to her wrongful conviction for the murder of her two children. The court used the probability of two SIDS deaths in the same family without considering genetic or environmental factors, which later led to her conviction being overturned.

  • What is the 'Simpson's Paradox' mentioned in the script, and how can it mislead data interpretation?

    -Simpson's Paradox occurs when a trend appears in different groups of data but disappears or reverses when these groups are combined. It can mislead data interpretation by showing a different overall story than the individual group trends.

  • What is the 'Prosecutor's Fallacy' and how can it lead to incorrect conclusions in legal cases?

    -The Prosecutor's Fallacy is the incorrect assumption that the probability of A given B is the same as the probability of B given A. This can lead to incorrect conclusions in legal cases, as it may misrepresent the likelihood of guilt or innocence based on certain characteristics or evidence.

  • Why are bar graphs that don't start at zero potentially misleading?

    -Bar graphs that don't start at zero can exaggerate differences between data points, making small changes appear much larger than they actually are. This can be used to mislead viewers by distorting the perception of the data's scale.

Outlines

00:00

🤰 Target's Pregnancy Prediction Algorithm

In 2002, Target sought a way to predict customer pregnancies using shopping patterns. Statistician Andrew Pole developed an algorithm that analyzed behaviors like lotion purchases and vitamin buying to identify expectant mothers and estimate their due dates. Target then sent coupons for baby products at the right time, subtly mixed with unrelated items to avoid suspicion. However, this approach backfired when a man discovered his high school daughter was receiving baby-related coupons, inadvertently revealing her pregnancy before she had told her family.

05:00

🔍 Misleading Statistics in Advertising and Court Cases

This paragraph discusses how statistics can be manipulated to mislead. An example is the UK ad for Colgate that claimed '80% of dentists recommend Colgate', which was misleading because dentists could recommend multiple brands. The paragraph also covers the misuse of statistical probability in court cases, such as the case of Janet Collins and Malcolm, who were convicted based on a mathematician's calculation of their guilt, and Sally Clark, who was wrongly convicted of murdering her children due to misinterpreted statistical evidence.

10:03

📊 The Dangers of Misinterpreting Statistical Data

The paragraph highlights the potential for misinterpretation in statistical data, such as the confusion between percentage increase and absolute increase in dropout rates. It also discusses the misuse of statistics in health scares, like the exaggerated risk of blood clots from a birth control pill, leading to unnecessary fear and consequences. The concept of correlation versus causation is explored, emphasizing the need for careful analysis before drawing conclusions.

15:03

📚 The Prosecutor's Fallacy and Misleading Graphs

This paragraph delves into the prosecutor's fallacy, where the probability of a given event is incorrectly assumed to be the same as the probability of the event given a condition. Examples include a case where an innocent couple was wrongly convicted due to this fallacy. Additionally, the paragraph addresses the misuse of bar graphs that do not start at zero, exaggerating differences and misleading viewers, as seen in various media examples.

Mindmap

Keywords

💡Statistician

A statistician is a professional who deals with the collection, analysis, interpretation, and presentation of data. In the video, the role of a statistician is highlighted through Andrew Pole, who developed an algorithm to predict customer pregnancies based on their shopping patterns, demonstrating the power of statistical analysis in understanding consumer behavior.

💡Algorithm

An algorithm is a set of rules or steps used to solve a problem or perform a computation. The video discusses an algorithm created by a statistician to determine the pregnancy of customers, which is a prime example of how algorithms can be used in data mining and predictive analytics to uncover hidden patterns.

💡Shopping Patterns

Shopping patterns refer to the behaviors and habits of consumers when they purchase goods. The video script mentions how an increase in lotion purchases and vitamins can be indicative of expectant mothers, showing how analyzing such patterns can lead to significant insights in marketing strategies.

💡Data Mining

Data mining is the process of discovering patterns in large data sets. The video illustrates data mining through the development of an algorithm that identifies pregnant customers by analyzing their shopping habits, which is a practical application of this concept in retail marketing.

💡Predictive Analytics

Predictive analytics is the use of data, statistical algorithms, and machine learning techniques to identify the likelihood of future outcomes based on historical data. The video's theme revolves around the use of predictive analytics to send targeted coupons to pregnant customers, highlighting its effectiveness in enhancing marketing strategies.

💡Correlation

Correlation refers to a statistical relationship between two variables. The video discusses the importance of distinguishing between correlation and causation, using examples such as head lice and health, to emphasize that correlation does not imply causation and can lead to incorrect assumptions.

💡Causation

Causation is the relationship between an effect and its cause. The video script warns against the common mistake of assuming causation from correlation alone, as seen in the discussion of violent TV shows and children's behavior, and the tragic case of Sally Clark, where incorrect assumptions led to a miscarriage of justice.

💡Prosecutor's Fallacy

The prosecutor's fallacy is a logical error where the probability of a hypothesis given the evidence is confused with the probability of the evidence given the hypothesis. The video script uses the example of a couple accused of a crime to illustrate how this fallacy can lead to wrongful convictions in the courtroom.

💡Simpson's Paradox

Simpson's paradox is a phenomenon in which a trend appears in several different groups of data but disappears or reverses when these groups are combined. The video script describes a scenario involving graduate school acceptance rates, where the overall data masks the actual acceptance rates when data is grouped by program, leading to a misleading conclusion.

💡Misleading Statistics

Misleading statistics occur when data is presented in a way that creates a false impression. The video provides several examples, such as the representation of tax cut impacts and high school diploma rates, where the use of non-zero baselines in graphs exaggerates the actual changes, demonstrating the importance of careful data presentation.

💡Epidemiology

Epidemiology is the study of the distribution and determinants of health-related conditions in populations. The video touches on this field when discussing the case of SIDS and the statistical evidence presented in court, which is a critical aspect of understanding the prevalence and potential causes of diseases in a population.

Highlights

Target's statistician Andrew Pole developed an algorithm to predict customer pregnancies based on shopping patterns.

The algorithm analyzed behaviors like increased lotion and vitamin purchases to identify expectant mothers.

Target used the algorithm to send timely coupons for pregnancy and baby-related products.

To avoid alarming customers, Target mixed baby-related coupons with unrelated products.

An angry father confronted Target over coupons sent to his pregnant daughter, unaware of her pregnancy.

The father later apologized after realizing the algorithm's accuracy in predicting his daughter's pregnancy.

A mathematician's testimony in a criminal case calculated the probability of an innocent couple matching witness descriptions.

The probability of 1 in 12 million led to a guilty verdict based on statistical evidence.

Sally Clark was convicted of infanticide based on a statistician's testimony regarding the rarity of two SIDS cases.

Misuse of statistics in Clark's case assumed independence of events that were likely influenced by genetic factors.

The misuse of statistics in advertising can lead to misunderstandings, as seen with Colgate's '80% of dentists recommend' claim.

Increases in percentages can be misleading; a 100% increase from 5% to 10% represents a 5% absolute increase.

Headlines can be misleading; a 100% increase in a rare event may not indicate a significant problem.

Misleading statistics on birth control pills led to women discontinuing use, resulting in unwanted pregnancies.

Correlation does not imply causation; head lice were once thought to improve health due to observed correlations.

The third cause fallacy suggests a third factor may be causing two correlated events, not each other.

Simpson's paradox shows that aggregated data can tell a different story than data grouped by categories.

Prosecutor's fallacy arises when the probability of two events given each other is incorrectly assumed to be the same.

Misrepresentation of data in graphs, such as not starting the baseline at zero, can distort perceptions.

Statistics can reveal intimate details of our lives or make trivial events seem serious, highlighting their power and potential misuse.

Transcripts

play00:00

Back around 2002 target came to a statistician with a question, in which is the answer

play00:04

could potentially make the company millions of dollars. They asked, "using only computers

play00:09

can you determine which customers are pregnant even if they don't want us to know?" and

play00:15

From then on statistician Andrew Pole was in search of an algorithm to do just that

play00:20

What he did was analyzed the shopping patterns of expectant mothers and noticed some common behaviors like an increase in lotion purchases

play00:28

Loading up on vitamins and more stuff that I know nothing about and he used this information

play00:33

To not only determine which customers were likely pregnant

play00:36

But what their expected due date was and after developing his mathematical model the statistician had a list of hundreds of thousands of women

play00:44

who were likely pregnant along with their expected due date and what trimester they were in and

play00:49

From then on target could send coupons at just the right time over the next several months and even after the baby was born

play00:56

Now, although target was cautious about following secrecy laws. It still might turn women away

play01:01

if all of a sudden they started getting coupons like cribs and diapers and other related items when they didn't in fact

play01:06

Tell the company that they were pregnant

play01:08

So what target did was just sprinkle these items in along with some other unrelated products when coupons arrived so it would seem more natural

play01:16

But about a year after creating this algorithm something happened though, and this is where it gets interesting

play01:21

One day a man walked into a Minnesota Target demanding to see a manager

play01:25

He was very angry

play01:26

and apparently what had been going on was target was sending coupons for things like diapers and

play01:32

Cribs and other related items to this guy's high school daughter and he was very upset about this

play01:37

He was saying things like are you guys trying to encourage her to get pregnant?

play01:40

And the manager didn't really know what was going on

play01:43

He of course apologized and a few days later the manager called the dad back to apologize again

play01:49

But this time the dad wasn't so much angry but a little more embarrassed

play01:53

I think you guys know where this is going. on the phone The dad said I in fact owe you an apology

play01:59

There's been some things going on around here that haven't been fully aware of and in fact

play02:03

My daughter is pregnant and she's due in August

play02:06

So yes this statistical algorithm figured out that this girl was pregnant before her dad even knew about

play02:12

That right there is the power of statistics and we're just getting started. In

play02:17

1964 an elderly woman was walking home from grocery shopping when she was all of a sudden pushed to the ground and had her purse stolen

play02:24

Now she was able to get a glimpse of the thief and saw a blonde woman in a ponytail who then fled the scene

play02:30

Then there was also a man nearby who heard the screaming

play02:33

And saw the woman run into a yellow car that was driven by a black man who had a beard and a mustache

play02:39

And yes

play02:40

This is all needed for the story by the way. a few days after the incident police ended up catching

play02:45

Janet Collins and her husband Malcolm who matched all the descriptions given by the witnesses

play02:50

They were then charged with the crime and put in front of a jury

play02:53

now since most of the evidence that could be provided for this was just from the victim and the man who saw the event and

play02:59

what they both witnessed they brought in a mathematician as well to help prove the guilt of this couple. This mathematician calculated the

play03:05

Probability of just randomly selecting a couple that was innocent

play03:09

But also happened to share all these characteristics that were observed by the witnesses. Based on data

play03:14

The mathematician came up with these numbers and assuming independent events

play03:18

We can multiply them all together to find the joint probability that they all happened to apply to an innocent couple

play03:24

Turns out there was less than a 1 in 12 million chance that this random couple who just happen to fit all those descriptions

play03:32

Was innocent, so the jury returned a guilty verdict

play03:35

This is actually a very famous case in terms of using statistics in the courtroom. Another quick example

play03:41

is that of Sally Clark who was found guilty of murdering her two infant son's back in the 90s. Her first son died suddenly in

play03:49

1996 due to unknown causes so it was assumed it was a case of SIDS, or sudden infant death syndrome

play03:55

But about a year later she gave birth to her second son

play03:58

Who was then found dead 8 weeks after his birth again of unknown causes

play04:03

So after this happened and it was reported, the police ended up arresting her and her husband on suspicion of murder

play04:09

During the trial a pediatrician professor

play04:11

Testified that the chance of two infants dying due to SIDS at around the same time relative to their birth

play04:17

Was about 1 in 73 million and again one in 73 million is way beyond a reasonable doubt

play04:24

so it was more likely this was an event of shaking or smothering or whatever and

play04:28

Sally Clark was found guilty and sentenced to life in prison

play04:31

So you can see statistics has a lot of power in our world whether it be advertising

play04:37

Criminal cases and so on but what's also really powerful and way easier to do is lie

play04:43

mislead and misinform

play04:44

Using statistics and you don't even have to use wrong data to do this

play04:48

I mean, I've already done that multiple times in this video. I'm going to talk about that soon

play04:53

so yes this next part for all you people who comment on videos before watching the entire thing because there is more I'm going to

play05:00

Say but let's start off light though. In

play05:02

2007 in the UK an ad was released for Colgate that claimed the classic "80% of dentists recommend Colgate"

play05:09

It wasn't long before the advertising standard authority of the UK ordered they abandon this claim because although it was true

play05:16

They knew people would not really understand what it meant

play05:19

The study that was done allowed dentists to answer with more than one toothpaste

play05:23

So like dentist one might say I recommend Colgate, crest, oral-b

play05:28

Dentist two might say Colgate, crest, or Sensodyne and similar for dentists three, four, and five

play05:34

In this scenario 80% of dentists do recommend Colgate. That is true.

play05:39

But 100% of dentists recommend crest in this hypothetical and 80% recommend oral B as well

play05:45

All of these numbers are factual and you can make an advertisement with any of these claims

play05:49

But again, we know people would not understand what they really meant

play05:53

now for this next part I'm going to ask you guys a question. If

play05:56

Let's say hypothetically the high school dropout rates of a certain country go from 5% one year to 10%,

play06:03

Is that a 5% increase or 100% increase?

play06:07

Because if you're at 5% and you add five you get to 10% obviously

play06:11

But if you're making let's say $5 an hour and you get a 100% raise you'll be at $10 an hour

play06:18

So which one of these is it and I'm sure many of you are saying that seems like a pointless question

play06:22

Yes

play06:23

You do add five to get to 10, but the physical amount of people who are dropping out would be increasing by 100%

play06:30

Well in the spirit of this video

play06:31

Let's ask something else. Which one of these paints a more accurate picture

play06:35

Like if one of these was posted in the New York Times or on Forbes or whatever

play06:39

Which one tells the people more about what's going on?

play06:42

And I'm actually curious what you guys have to say about that because I think we're gonna hear different answers from different people

play06:47

But for this next part, I think we're all going to agree

play06:49

What if hypothetically the dropout rates are one in a million people and then the next year they go to two in a million people

play06:56

So that's .0001% to .0002%, a difference of again .0001

play07:03

But that's also a 100% increase in the physical amount of people dropping out

play07:08

So which one of these two headlines do think paints a better picture?

play07:12

Well again, we might hear different answers

play07:14

But I think we can agree the 100% makes it seem like a worse problem than it is

play07:19

Like if five people in the whole nation are dropping out and the next year ten people do I

play07:24

Wouldn't necessarily call that an epidemic just yet

play07:26

Now using numbers like this in the misleading way is actually not hypothetical because it happened a few decades ago in the UK

play07:32

But not with college dropout rates, but rather a birth control pill. In

play07:37

1995 the UK Committee on safety of medicines issued a warning that a certain type of birth control pill

play07:42

Increased the risk of life-threatening blood clots by 100%

play07:46

What that actually meant was that with the older second-generation pill about 1 in 7,000 women developed a blood clot

play07:52

Whereas with the new pill about 2 in 7,000 women developed a blood clot

play07:56

So yes, the physical amount of women receiving a blood clot did go up by a hundred percent. That is true

play08:01

But if we dig just a little deeper we see with the older pill is about .014%

play08:07

Whereas with the new pill it was about .028%, which hardly seems worthy of a breaking news alert

play08:13

But articles were posted about this misleading statistic and as a result naturally tens to hundreds of thousands of women stopped taking this birth control

play08:21

pill

play08:21

fast forward one year and that scare was blamed for

play08:25

13,000 unwanted pregnancies many of which were teenage pregnancies... a lot of teenage pregnancy stories in this video... moving on

play08:32

Do you guys actually know head lice is good for your health?

play08:36

Seems pretty stupid

play08:37

Right, but people actually thought this at one point and that brings us to the part of this video titled correlation or causation

play08:44

or both

play08:45

Remember, it's usually very easy to determine that two things are correlated from a statistical test but causation is a completely different thing

play08:52

That isn't so easy to spot. yet

play08:54

People are very quick to assume that A causes B just because A is correlated to B

play08:59

Sometimes the logic can be stupidly obvious like fast-moving wind turbines are positively correlated to fast wind. As one goes up

play09:06

The other goes up, but does that mean that fast-moving wind turbines cause fast wind?

play09:11

Well, obviously not it's the other way around

play09:14

But in many cases it isn't this obvious like what if I said that kids who watch more violent TV shows are more violent themselves

play09:21

Does this mean that those shows cause kids to be more violent?

play09:24

I mean that could be possible and definitely would be an immediate thought for many people

play09:28

But what if kids who are more violent just happen to watch more violent TV shows that also seems perfectly reasonable

play09:34

So we can't just jump to conclusions too early

play09:37

Even though that's what many people would probably do. Or in the Middle Ages European

play09:41

Saw that people who had head lice were normally healthy. Whereas people who were sick rarely ever had head lice. as a result

play09:47

They assumed that lice would cause people to be more healthy when in reality head lice is very sensitive the body temperature

play09:53

So people had a fever or anything like that the head lice would find another host

play09:58

Then on the subject we have the third cause fallacy where two correlated events

play10:03

Actually, don't cause each other at all, but it's rather a third thing causing both. For example ice cream sales

play10:08

Do not cause an increase in heat strokes nor the other way around

play10:11

Even though they are correlated. Hot weather is instead the cause of both of them. Or for the past several decades

play10:18

Atmospheric co2 has increased along with obesity levels. So does one cause the other

play10:22

Well, no richer populations tend to eat more and also produce more co2

play10:28

And sometimes it can just be really unclear what's causing what.

play10:31

Like a while back they found that students who smoke cigarettes get lower grades and that could mean smoking causes lower grades

play10:38

Or maybe it means that getting bad grades causes smoking... Maybe the added stress that comes along with lower grades

play10:45

Increases the chance that a student will pick up that first cigarette. That also seems like a reasonable explanation

play10:51

Or it could be a variety of third factors is actually responsible for both

play10:56

So even when looking at a statistical test with accurate numbers, it's pretty crazy how far you can still be from the truth?

play11:03

Next we have a story that will probably have people making assumptions really early in the 1970s

play11:08

Someone noticed that Berkeley was accepting 44% of male applicants to their graduate school

play11:13

But only 35% of female applicants. Now right there half the Internet's like well say no more...

play11:31

But only 35% of female applicants

play11:59

play12:04

That was an actual unedited clip of everyone on the Internet

play12:09

Now these numbers that we saw are true

play12:12

But very misleading when you look at how male and female applicants applied to each program within the Graduate School the assumed bias

play12:18

Not only goes away but kind of flips. Look closely here in this row

play12:23

You see there was a high acceptance rate for the program

play12:26

In fact women had a much higher acceptance rate, but still overall it was high for everyone

play12:31

however way more men applied to this one

play12:34

Whereas more women applied to these programs down here with much lower acceptance rates

play12:39

So since a higher percentage of women were applying to these programs with higher rejection rates

play12:43

The overall acceptance of women would be lower guaranteed even though they are in fact slightly favored across a couple of departments

play12:50

so either of these headlines could be published with the necessary stats to back them up and

play12:56

All you gotta do is pick which one you want to use

play12:59

toss

play12:59

the other

play13:00

Throw that into an article put it in bold right on the top, put the cleverly selected statistics down below it to back it up,

play13:07

And you've got yourself a story

play13:10

This here was an example of Simpsons paradox

play13:13

Where looking at data as a whole tells a totally different story than grouping the data appropriately which I'm sure many of

play13:19

You know, but I had to include it here

play13:21

You guys remember the story of the blonde woman who robbed the elderly lady

play13:25

Well, like I said, this is a famous case but not for the use of statistics

play13:30

But rather the misuse of statistics in the courtroom, this was a classic example of the prosecutors fallacy

play13:37

now this fallacy comes up when people assume that the probability of A given B is the same as the probability of B given A

play13:44

Which I'm sure many of you know is not usually true from this equation.

play13:48

Like if I said behind this curtain is an animal with four legs, that's the given. What is the chance that it's a dog?

play13:56

Well, you probably do some thinking like well, it could be a dog, it could be a cat, it could be a cheetah

play14:01

It could be a lot of other things and if you had to come up with a number you might say one in a hundred

play14:05

One in a thousand or whatever, but if instead I said behind this curtain is a dog

play14:10

That's the given, what's the chance that it has four legs?

play14:14

Well, that's almost a guarantee because most dogs have four legs

play14:18

So you see switch the given and the question at hand and the probability can change by a lot

play14:24

So now let's look at what I said earlier

play14:27

Turns out there was less than a 1 and 12 million chance that this random couple who just happened to fit all those descriptions

play14:34

Was innocent, so the jury returned a guilty verdict.

play14:38

This here was wrong

play14:39

The stats actually showed us that given an innocent couple the odds that they fit the descriptions was one in 12 million

play14:47

But then I said what the jury had also assumed that if you switch the given and the question at hand

play14:53

The probability stays the same which we just saw can be very wrong

play14:58

This left side should make sense like if I just grabbed a random couple out of a mall

play15:03

That's the given there was a very small chance all of these would apply to them

play15:07

But this is the false assumption that is the prosecutors fallacy

play15:12

We're told or given

play15:14

Hey

play15:14

Here's a couple that fits all those descriptions. If maybe ten people in the entire city fit all of those given a random one

play15:21

There's a 1 out of 10 chance that they're guilty or a 9 in 10 chance of being innocent. Not one in 12 million.

play15:29

And remember Sally Clark who was found guilty of murdering her two children

play15:33

This is also a famous case of the misuse of statistics

play15:36

It turns out bacterial tests had actually been withheld that would reveal more specific information than a simple multiplication of two probabilities

play15:43

Which didn't tell the full story at all.

play15:46

Like it assumed that the two events were independent of each other when genetic or environmental factors could have definitely been at play

play15:53

Like I said, sally was found guilty and sentenced to life in prison

play15:56

But she only served three years when the convictions were finally overturned in early 2003. Up until then though

play16:03

Sally Clark was widely criticized in the press as a child murderer

play16:06

And she was never able to recover mentally from the false accusation. A few years after her release

play16:11

She developed psychiatric problems and died in her home from alcohol poisoning in 2007

play16:17

I'm gonna repeat that for everyone who didn't follow it. A woman lost two of her children due to natural causes

play16:24

was accused of murdering them, was put on trial and found guilty due to a misuse of

play16:29

Statistics, spent 3 years in prison, and even after her release was not able to recover mentally and died

play16:36

Just about four years later

play16:37

If you guys don't find that story

play16:39

Insane then I don't know what to tell you

play16:42

And actually the result of this case prompted the Attorney General to order a review of hundreds of other similar cases

play16:48

Now because I don't want that to be where we end this video

play16:50

Let's look at one more classic misuse of Statistics

play16:54

This one has to do with how data is represented and it often involves bar graphs that don't have zero as their baseline

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For example FoxNews one showed a chart detailing the numbers what would happen if the Bush tax cuts expired?

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Do you guys see a problem?

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Yeah

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It starts at 34 percent at the bottom making a not even 15 percent increase look like a few hundred percent in

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Reality the chart should look like this

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Or take the Terri Schiavo case that occurred about two decades ago

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Which involved a debate of whether a feeding tube should be removed from a woman in an irreversible vegetative state

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During that time CNN posted this graph detailing which political parties agreed with the courts

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It seems like Democrats supported the decision significantly more but because the baseline is not zero

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It appears way different than it should, this is what the actual graph would look like

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Or in 2015 the White House published a tweet about the increase in students receiving high school diplomas with an extremely misleading graphic

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They made around a ten percent increase look like nearly 200%. Or in music

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There was a chart released showing views between top artists that made drake look like he was ahead by a large margin

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When in fact it was about a five percent lead

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Now I'm guessing the comments on this video will be rather interesting

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But remember these were cherry-picked events and it's not like everything. I said paints the full picture either

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I just find it interesting that these numbers can change the way we think about a person

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They can peek into some of the most intimate moments of our lives based on our grocery list

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They can make very trivial events seem very serious and vice versa

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You don't even need use wrong numbers for this

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But hopefully this show just how not cut and dry math and statistics can be in the real world outside of a school setting

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Especially and with that I'm gonna end that video there if you guys enjoyed be sure to LIKE and subscribe

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Don't forget to follow me on Twitter and try them in facebook group for updates on everything hit the bell if you're not being notified

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Share comments and all those other YouTube boards and I will see you guys in the next video

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Etiquetas Relacionadas
StatisticsAdvertisingLawTargetPregnancyMisleading DataAlgorithmCrimeCorrelationCausationMisuse of StatsBirth ControlDropout RatesHead LiceSimpsons ParadoxProsecutors FallacyBar Graphs
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