A Rubbish Graph

Introduction

The tile of this page is very direct and it should be. I came across the graph that you will se below the other day and I was shocked that an organisation like Deloitte's would publish it and that the US Census Bureau would create it.

The purpose of this page is to show you the graph and then to show you what it should like.

Then someone has to hold up their hand an admit that there is no excuse for such a rubbish graph these days.

Please note, I am referring to the technical aspects of the graph and I am not attempting in any way to assess any underlying agenda.

The Graph

Just take a look at the following graph and ask yourself if it looks good to you

If you think it looks good, look again:

• In column one we see the small bar with $40k on top of it
• In column four we see the largest column with $81k on top of it

However, even though 81/40 is almost exactly equal to 2, it took me over five of the small bars from column 1 to stack them to be equivalent in size to column 4. Similarly with the other columns. The scales are rubbish!

Solve the Problem

 The problem is, of course, that the scales they have used in drawing the graph are all wrong and all we have to do is to draw the graph again using the values 40, 50, 68 and 81 to create a column graph, like this one:

Can you see the difference between their graph and mine? Can you appreciate the point I made about the absolute and relative size of the bar in column one?

Good! the graph is now corrected! How on earth they ended up with that rubbish graph is not beyond me as I present my attempt at doing that below:

There you are, without getting right down to pin point accuracy, I have pretty well got the first bar down to the same size as the original. How did I do it? I changed the vertical scale to change from 0 to start at 27.5. Then I hid the scale from the graph. I have not added the data labels so that I can question their inclusion in the original graph.

Why Include the Data Labels?

If I am seeking to deceive and I have changed the scale of one or more axes on a graph, I can deflect attention away from the deception by drawing your attention to something else. The aim being to try to ensure you wouldn't notice the rubbish scale. I did say I wouldn't talk about positive deception but I couldn't avoid it, could I?

There you are: it's easy to deceive with an Excel graph but it's even easier not to!

Download the Excel file from here: 

Duncan Williamson

27th March 2022