Statistics is a branch of mathematics that is not studied by most people and therefore not clearly understood by them, thus leaving them open to being misled by the information presented to them – a fact recognized in the 19th century when the phrase ‘Lies, Damned Lies and Statistics’ came to prominence and which described the persuasive power of statistics to bolster weak arguments.
This particular phrase was the subject of a recent talk to the Bakewell and District Probus Club by one of its members, Paul Davies, who is himself a mathematician. Paul started with a definition of statistics as the collection, analysis, interpretation, presentation and organization of data such that the main goal is to provide a quantitative and objective approach to understanding and interpreting the data. He continued by describing the history of statistics, how they can be used to great benefit, but also how they are often manipulated with the intention to deceive.
It was on this latter aspect of his subject that he concentrated much of his presentation, by showing examples of the misleading ways in which advertisers, politicians and others selectively make use of statistics to support the particular assertions being made by them. As an example of one of the many advertisements which he illustrated, a toothpaste (let us say, Brand X) is claimed to be recommended by 80% of dentists. This may be true – in a survey, four out of five dentists may indeed have recommended Brand X, but what the advertisement does not reveal is that, in the same survey, all five of them (i.e. 100%) would also recommend Brand Y, a competitor. The speaker also showed examples of the ways in which mathematically correct information can be depicted in such a format on a graph as to give a totally distorted picture.
Summing up his talk, Paul pointed out that, despite the potential for giving misleading information, well collected, analysed and presented statistics can help decision making and communication, but there are multiple ways in which data can be twisted, interpreted and creatively presented. Therefore his message was that we should check, question and challenge what is presented to us.
Details of the Bakewell and District Probus Club, including reports of earlier meetings, can be found on its website at www.bakewell probus.org