# Naked percentages – and other ways PRs slip up with numbers

I train PR practitioners in working with, and communicating, numerical information.

I’ve put together the following five ways that tell me someone isn’t necessarily comfortable with numbers, data and statistics.

1 – Naked percentages – look away now!

Percentages. No other topic can conjure the same look of terror on those who come to my workshops. And a naked percentage even more so!

And when I’m reading press releases – especially those reporting survey research – it’s the abundance of “naked percentages” that often suggest the writer wasn’t comfortable.

It’s this sort of thing (paraphrased from a real example):

“We found that 8% of women and 9% of men thought of a thing every day compared to only 5% of adults who thought of another thing entirely. Of the people who thought a lot about the thing, 77% stated it was because it made them happy – while 61% said it was because it was a nice shape.”

I call percentages that just stand there in all their glory, naked percentages. I recommend that most – if not all – percentage figures be “clothed”, ie in brackets following an interpretation in words. Something like this:

“We found that a little under one in twelve (8%) women and one in eleven men (9%) thought of a thing every day, compared to only one in twenty (5%) adults who thought of another thing entirely. Of the people who thought a lot about the thing, just over three quarters (77%) stated it was because it made them happy – while three fifths (61%) said it was because it was a nice shape.”

A couple of reasons for doing this … it’s easier for the reader to imagine twelve women and picture one of them in particular. And if you are working with an infographic designer you’ll have given them a head start on their work.

To make this easier for me and others, I’ve put together an Excel spreadsheet to generate phrases you might want to use in your writing. I’ve also developed simple tweaks for Word so that as you type the numbers it automatically inserts an appropriate phrase.

2 – Pi(e) in the sky precision

How many digits of pi can you recall? Here are a few … 3.1419526535879.

How precise do you need pi for practical purposes? If you’re guiding the International Space Station, 15 it seems. But for most of us, four is probably more than okay. And for rough approximations 3 or 3.1 could well be enough.

The same principle counts for PR.

You don’t need that many figures to make your point. Yet, so many people are tempted to go over the top with precision. A paraphrased example: “We’ve lost 45.01 per cent of our social referrals.”

What does that extra “.01” add? That’s down to a level of 1 in 10,000! There’s probably more noise and error in the measurement than that. My experience is that quoting more than three significant figures readily loses an audience – especially if it’s done for every figure you’re presenting.

I think people like the extra precision because they think it means accuracy. But it only implies it. The eagle-eyed among you may have spotted that the figure I’ve given for pi above is wrong. I’ve deliberately switched some figures. Other than for working in space, you’d be fine using it.

And this is another reason to avoid unnecessary precision – the more numbers you have to type the more chance you have of inadvertently typing them wrong. Stick with the 45 per cent not the 45.01 … cos one day you’ll type 40.51 per cent without noticing

3 – Average but untypical – do you mean to use the mean?

Anything in which an average is quoted grabs my attention. Sadly, usually for the wrong reasons.

By “average” most people don’t mean the sixteenth century custom duty. They mean the mean. Specifically the arithmetic mean – count the numbers; then add them up; divide the result of the latter by the result of the former.

Statisticians and other number-wranglers have come up with lots of different averages. All are intended to summarise the data in a way that gives insight into what is typical or expected – in jargon, a measure of central tendency.

Here are nine numbers: 500, 4, 1, 200, 3, 1, 5, 1, 5. What is the average? Here are three ways of giving an answer:

 Type of average Result The arithmetic mean – add all up and divide by 9 80 The median – line up in order and find the middle number 4 The mode – single most frequently occurring 1

The mean is 80, bigger than seven of the nine numbers. The median (4) is within 3 of seven numbers. The mode is within 4 of seven numbers, but is the lowest number of them all.

Which is the most appropriate? In real life it is often a question of what most of your audience will feel is typical of their own experience – get that wrong and no matter how good your message, you’ve probably lost their confidence already.

4 – Data butter or data marge? Spread matters!

The choice of average depends a lot on the distribution of your data – how the numbers are spread out. What’s highest? What’s lowest? Do most numbers bunch at one end or the other, or in the middle?

For a lot of PR work, these questions should be asked before any calculations are done, and definitely before anything gets written up.

And the best way to do that is to visualise the numbers. You don’t have to be a whizz with Excel charts to do this. Grab a pencil or pen and a piece of paper – and sketch. For the numbers above, this is my ten-second effort:

Anything which is skewed – the bunching is not in the middle but at an end – strongly suggests that the mean is not going to be a good average. The overly high (or low) numbers will ‘dominate’ the calculation and the result will send the wrong message.

5 – A picture paints a thousand words – but does it have a bit of the Jackson Pollocks?

You might not want to present your one-minute sketch. But a good graph can make all the difference to gaining understanding. And a strong infographic can readily go viral.

If you’re using a traditional chart or graph there are some basic rules that should never (well, very rarely) be broken. It’s a long list so I won’t go into everything here.

But here are a few …

Percentages in pie charts should add up to 100 … unless you’re Fox!

Even the smallest table needs the numbers to make sense … CNN take note!

Bar charts should start at zero … this one looks like it’s been booted over the bar!

And with infographics there is so much more to get right – and wrong. Not least that you’ll get your numbers right but still send a damaging message. For example, be careful that your stylisation of typical people isn’t stereotyping … is this perpetuating notions of what are ‘male’ and ‘female’ jobs?