Crawford Hollingworth: Making sense of numbers

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We all know the importance of plain English for improving consumer understanding and decision-making. Much has been written on how to write effectively. Most recently, Harvard behavioural scientists Todd Rogers and Jessica Lasky-Fink published Writing for busy readers: Communicate more effectively in the real world.

Sadly, we have not seen the same focus when it comes to tackling numerical blindness, yet many lack basic numeracy skills, with the UK one of the worst performing nations in the Organisation for Economic Co-operation and Development. A 2011 survey found that nearly half the working-age population has the numeracy levels expected of a child aged 9 to11. Only a fifth are what we call functionally numerate – the equivalent of a GCSE grade 4 (C) or above.

Chip Heath, professor of organisational behaviour at Stanford School of Business, has said: “Maths is no one’s native language. At best, it is a second language, picked up at school through formal training.”

Just as behavioural science has highlighted how plain English can increase comprehension and action, it has also shown how to communicate ‘plain numbers’ – making numerical information easier to comprehend. Simply disclosing numbers to consumers is not enough, particularly in the context of the consumer duty that took effect from the end of July 2023.

Two behavioural science-inspired principles can help us tackle number blindness: cognitive ease and anchors.

Building cognitive ease

We experience cognitive ease when information is presented in a way that requires minimal mental effort to absorb and understand it. When it is presented in this way, allowing the ‘reader’ to make decisions using more of their automatic or effortless (System 1 ) thinking, we can say information is high in ‘cognitive ease’. Conversely, if people are forced to engage System 2 – where it takes more effort to comprehend information – they are less likely to act on the information and may give up trying to read it at all, particularly if they are busy.

1. Where possible, avoid using numbers
   
   The first rule of thumb for communicating numbers simply is actually not to use them at all. Take a Bloomberg headline from April 2023: “Women CEOs (finally) outnumber those named John”. It is equally possible to make the statement using numbers: “For the first time, there were 41 female CEOs in the S&P 500 and only 23 Johns or Jons out of a total 500 CEOs”. However, the key message to convey is that the number of female CEOs is still small but rising, and this doesn’t need numbers. A simple verbal comparison is clearer and more memorable. Make your point without numbers if possible, but, if they must feature, identify only the key figures, and cut the rest.
2. Make numbers simple or shorter
   
   There is a long-standing debate about the trade-off between precision and comprehension when it comes to rounding numbers. On the one hand, it feels intuitive that people would prefer rounded numbers. Indeed, research has found that people find single-digit numbers easier to remember than teen numbers, and double numbers – for example, 33 – easier than other double digits. Yet, there is also evidence that we are more likely to believe a precise number is true – the likelihood of being able to precisely measure an unfamiliar quantity with round numbers is extremely low. When an expedition team measured Mount Everest to be 29,000ft, they opted to report it as 29,002ft to remove any doubt that they had rounded it.
   

A recent study (Nguyen, Hofman and Goldstein, 2022 ) set out to test the impact that rounding has on people’s ability to remember numbers. Researchers asked participants to read news snippets that cited numbers in either a precise or rounded format and then recall them. For example: “Among the admitted students were 28,752 ( 30,000 ) transfer students who were offered spots at UC campuses”. When researchers compared recall accuracy, less than 50% of responses in the precise condition were approximately correct, versus nearly 70% in the rounded condition. People were also more likely to make faster estimations in the rounded condition.

Many people fall into the trap of using big numbers to sound impressive. Politicians tend to use phrases such as “we will spend a further £200m on the health service”, knowing this sounds like a large increase to most people, whereas, in reality, it is a meagre amount in a government budget. Some neuroscientists argue that our brains were probably not built to comprehend the differences between large numbers, as 1,000, 1m or 1bn are all ‘big’.

Give numbers anchors for context

We need reference points or anchors to put a number into context and aid understanding, particularly when the context is unfamiliar. We can also add emotional meaning by framing numbers, which can help people focus on the most important aspect, such as key benefits or drawbacks.
Make numbers meaningful by providing comparison points. Chip Heath believes that we need to paint a picture with numbers and make them emotionally meaningful. In an interview for a January 2022 episode of Stanford University’s Graduate School of Business’s ‘Think Fast, Talk Smart’ podcast, he said: “We have to make data emotional because emotions are what drive us to act.”

In 2016, researchers from Microsoft and Columbia University (Barrio, Goldstein and Hofman) set out to make headlines more meaningful by adding contextual perspective clauses. For example, “The storm killed thousands of people in Honduras, left one million homeless... To put this into perspective, one million is about 12% of the population in Honduras”, and found that people were more likely to recall the number accurately.

Summary and implications:

Consider starting by assuming people likely struggle with numbers

• When exploring communication that involves numbers, keep in mind different levels of numeracy, and design your sample, or use the screener, to ensure you can research a good spread of numeric ability
• When thinking about your audience, it is best to measure both objective and subjective numeric ability, as people often think they are better (or worse) with numbers than they actually are
• If you need to communicate numbers, think about how best to communicate them, or how to bring the numbers alive. Remember there are many ways to communicate the same number – behavioural science is your creative friend.