What is it about?
According to its authors: “Mathematics scares and depresses most of us, but politicians, journalists and everyone in power use numbers all the time to bamboozle us. It is liberating to understand when numbers are telling the truth or being used to lie.”
According to Steven Poole at the Guardian: “This very elegant book… constantly sparks “Aha!” moments as it interrogates the way numbers are handled and mishandled by politicians and the media.”
The Tiger that Isn’t isn’t just a book about statistics and how they are used to tell stories, it also provides the antidote to spin. It teaches you how to ask the questions that will cut through the rhetoric and explains how to use numbers to understand what is really going on.
Book structure
Dilnot and Blastland discuss a multitude of statistical tricks and sleights of hand. They cover everything from averages to sampling and randomness to target setting.
Numbers sound cold hard and unequivocal, but they can be deceptive when taken out of context. The book is full of examples:
- Mrs Thatcher’s government changed the definition of “unemployed” twenty three times during the 1980s.
- In the UK almost everyone has more than the average number of feet.
- Should you allow yourself to be treated by the surgeon with the highest death rate in the country?
Blastland and Dilnot explain why Albert Einstein was right when he said “Information is not knowledge.”
A story from the book
The following morning the mast operator, T-Mobile, couldn’t reach the site at Wishaw in the West Midlands. An angry crowd of locals refused to let them pass.
The locals blamed the mast for causing an outbreak of cancer. There had been twenty cases of serious illness in the eighteen houses that surrounded it. These included cancers of the prostate, lung, bladder and breast. One man was dying of motor neurone disease.
The Department of Health investigated the incident and said that there was no statistical evidence of a cancer cluster. The mobile phone company showed that the microwaves emitted from the mast were well within the levels permitted. Yet despite these reassurances the mast has still not been replaced.
So was there a cancer cluster or not?
The book doesn’t wade into the argument. But what it does do is explain how randomness plays tricks on us and how we see causal relationships that don’t exist.
Imagine standing in the middle of an empty room, then taking a bag of rice and throwing it into the air. The rice will land randomly on the floor. In some places there will be clumps, others areas will have a light scattering and some parts of the floor will be completely clear. Are the clumps of rice caused by some single factor, or is it simply randomness at play?
How would you feel if the rice was perfectly evenly distributed across the whole floor?
Where the book wins out
The book provides clear guidance about the questions to ask when people start arguing with numbers.
When faced with a large value…
You should always ask “is that a big number?” Work out what that number means for you as an individual.
When faced with a causal relationship…
Don’t jump to a conclusion, generate some other hypotheses. Think through what else could be causing the outcome.
When faced with a statistic…
Ask where the statistic came from. Who is counting and what definition did they use?
When faced with performance against a numerical target…
Look at the bigger picture because targets are narrowly defined. What else could be going on? What does the target statement hide?
Worth a read
The book is easy to understand and contains some fascinating stories. It will make you think twice next time a politician or journalist tries to spin some statistics your way.
You will also start to question the numbers that are bandied about in your own organisation.
You can find a copy of “The Tiger That Isn’t” on Amazon.
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