« Digging it out | Main | Horrid stuff 2 »

TrackBack

TrackBack URL for this entry:
http://www.typepad.com/services/trackback/6a00d8341e992c53ef00d835183fbb69e2

Listed below are links to weblogs that reference Horrid stuff:

Comments

derek

I think this is a case for exploratory data analysis. I'd like to know that a similar pattern was visible when the graphs were plotted in order of maximum particulate pollution as well as maximum NO2 pollution. And when the minimum and midpoints of each were plotted instead. If only one of the six combinations showed any visible pattern, and the sixth was what was published, I'd cry "Cherry picking!"

Also, scatter graphs would be the medium for displaying correlations, surely? haven't you railed in the past about plotting two time series side by side and claiming a correlation by virtue of the series looking similar when the scales are adjusted? This is just the same thing, but with a category (city) in place of time. My alternative, then, would be to plot a scatter graph of max and min pollution, and look for those lines to run south east instead of north east.

TheRandomTexan

Right on, derek!

If scatterplots are too difficult, it would be a big improvement to see box-and-whisker diagrams, rather than just range bars. Any time I see only one statistic used, e.g. mean, median, or range, I immediately ask "What are they not telling us?" Certainly the European Environmental Agency has data for a boxplot.

derek

plotting two time series side by side

Sorry, I should have said "superimposed", not "side by side". The articles I had in mind are probably these two:

Dissecting two axes

The Crossover Law of Petropolitics

Kaiser

At first I was going to do a scatter plot. But then I'd have to pick one of max, min, median, etc. I absolutely agree with the EDA comment. It's very unclear to me what their "ranges" mean, especially when some of the intervals are much wider than the others. Perhaps some of our readers are in this field and can offer help in interpreting the data.

Jon Peltier

I don't see much reverse correlation in the two pollutants. The ranges are too borad and not enough is known about the relative concentrations of the pollutants at different times. I've made my own chart and given a brief analysis on this page:

http://peltiertech.com/Excel/Commentary/HorridStuff.html

Armin

Actually, you can design an engine (car, plane, power plant, etc.) either towards low NOx or low soot emissions. So the negative correlation doesn't really surprise me :-)

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Marketing analytics and data visualization expert. Author and Speaker. Currently at Vimeo and NYU. See my full bio.

Book Blog



Link to junkcharts

Graphics design by Amanda Lee

The Read



Good Books

Keep in Touch

follow me on Twitter

Residues