Statistical Significance

It’s been a while since I blogged. So what better topic to get back into the swing of things than Statistical Significance? (I know! How have I gone this long without one?!)

I like to think of statistical significance as one of those things that I can get excited about, so you don’t have to. And, if I’m really honest, few of my clients do get all that excited about it. That’s their loss. But they do often appreciate the insight it provides. I consider it part of my overall strategy for turning data into stories. After all, if you’ve got both then you’ve got more ways to convince more people of your truth.

So, if I’ve got a load of results from:

• a survey
• a series of 360 reviews
• focus groups who have scored some qualities of where they work

Then I can rank those scores top to bottom. And I can produce some nice tables and charts. I can tell you what the top 5 and bottom 5 are. Or top 10 and bottom 10. Or, well you get the idea. But what’s to say the top 5, 10, whatever are the most important?

If people have grasped any statistical concept, then it tends to be that of the bell curve. You can picture the shape, and you probably understand that in a “normal distribution” most results will be in the main body of the curve – the bulgy bit. They may be high or low, but if they’re in the middle, then that highness or lowness isn’t yet significant. It’s only when they move to the left or right that they get more interesting.

So I’ll look at your results and tell you what are the significant top x results and the significant bottom y results. Those that are apart for the rest of the results; those that people feel most strongly about. Of course, I’m conscious of “lies, damn lies and statistics”. Sometimes I’ll use a standard deviation, sometimes an average deviation – it’s got to be what throws most light on the data.

That gives me – and my clients – more confidence that we’re looking at the truly important, symbolic or compelling results. And we can build that into a more powerful narrative – of what’s being said, what needs changing and what should be done.