Friday, October 2, 2009

Some data... quote Demetri Martin. I've just come across a bad graphs at First off, is a pie chart of the different browseres used on

So what's wrong with this? First off all, pie charts are depending on us camparing areas to each other, and we can't do that very well when there are some many. So this is the wrong type of chart. To make it even worse, the gradient, shading and 3D-effect makes it even harder to compare the ares. The alignment of the numbers can also have an effect to make the perceived area larger or smaller (though there aren't any really good examples on this chart). They should at least have ordered the slices in decreasing or increasing size. Also, the legend on the right makes your eye go back and fourth to match the browser with the corresponding slice of the pie.

A simple table would have made these data much more available and faster to explore for the reader.

But since I'm in a mood for exploring the possibilities and limitations of Excel and improve my presentation/ charting skills, I've suggested a better graph:
I made this just with Excel, no editing. The numbers next to the where made using a "fake" second series with value 0% and named after the value of each browser share, and I use series name as data label, aglined to the left. I would have loved if Excel could do that automatically, and to be able to formate each of the labels individually. For example, I would prefer to have the "%"-sign a couple of points smaller then the number. Also, I think the point of the author was that IE6 is now used of less then 10% of the users. To emphasise that, I could have given the IE6 bar a red color. But, when it comes to colors, I prefer the following rule:

So, I made a version in black and white. Slightly less fancy, but it does get the point across:
Yes, I could have worked a bit more with selecting the greys, but this is the default grey's in Excel 2003.

Next up was a line plot showing the trends over time:

Line plots greatest strength is to show trends over time, so in that case, they've choosen the correct type of chart. But there are some bad graphing here as well: The background gradient takes too much attention, the alignment of the titles of the axis are wrong (they should be horisontal), your eyes again has to go back and fourth between the legende and the plot, etc. But my main concern is the numbers on the lines. First of all, they don't add up to 100% (just sum the numbers on the right end) and especially from sept. '08 march '09 it's really hard to read the values on the smallest browseres. I even had to "guesstimate" the values there when I made my own version. Line plots does not do a good job of presenting individual values, bar charts are much better at that. Or a table. So my suggestion for improving this graph, is a combination of a line plot and a table, to get the best of two worlds:
Again I could have spent more time on the colors, but I used the standard palette in Excel 2003. What I really would want to be able to do here, is to formate the table better, so make the legende and headers stand out from the data. But here I'm falling short, I don't even know how to "cheat" in Excel to make that happen. Any suggestions? Still, I do feel my suggestion is clearer and better then the default ones from


Wilhelm said...

...exactly what do you want to have done with the headers and labels? Bigger font? Bold font?

Jon Peltier said...

Nice job.

Anders said...

Hi Jon,

I'm really surprised and excited by seeing your comment here. I love your site and I've learned a lot from it. MS Excel should come with a print-out of your tips and tricks.

Anders said...

Wilhelm: I would love to be able to have full control over the layout. Using bold or grey color to separate the legend and categories from the data. Adding background color to each individual line in the table to guide the eye. Etc, etc.

Eyvind A. Larre said...

Hi Anders.
Thanks for using our graphs and showing what is wrong with them. We must obviously do a better job next month when publishing new statistics and graphs.

Anders said...

Hi Eivind.

Thank you for your comment. I'll drop by the next months and check it out.

Anders said...

As promised above, I did drop by Finn. And it seems that they still use that old pie chart. 3D tilting, shadow- and gradient effect distorts the data, and should be avoided. In fact, 3D plot should never be used to represent 2D data. But according to, the pie shows the same as the line chart, but " artige fargede kakestykker i stedet." ("...with amuzing colored pie slices instead")... Oh well.

Not that I did expect Finn to change anything, though, but I promised to check it out.