I can’t quite decide whether this is a Truly Unfortunate Representation of Data. Help me out here.
The following is from an Educational Researcher article on the alignment between the math and English/language arts standards of various states and those of the Common Core State Standards (about which, more here).
The graphic (and several others like it) comes with the following disclaimer:
When reading these graphs, the representation of content emphasis is accurate at each column- by-row intersection, but the smoothing between rows and between columns is not meaningful because the data are nominal. (p. 107)
What this means is this, Because the data is categorical, we could really have put them in any order we like. As a consequence, any patterns (any patterns!) we see within each graph are simply artifacts of the order we chose. This smacks of TURD to me. But I stand ready to be convinced. Any takers?
Porter, A., McMaken, J., Hwang, J. & Yang, R. (2011). Common Core standards: The new U.S. intended curriculum. Educational researcher, 40, 103—116.
I can just hear some graphic designers voice in the background…
“But it looks cool.”
And also, But the software is set up to do it.
The graphics are bad, but their tabular representation was worse, having ridiculous numbers that did not correspond to their graphs at all. The whole study appears to have been badly conducted and badly presented, so the terrible graphics may be the best part.
Well pointed out, Chris.
I am reminded by a comment by Michael Crichton in a novel in which it was pointed out that whilst computers handle raw numerical data best, human beings prefer graphical images to make sense of data.
What a shame when the graphic is so misleading that non-numerate readers won’t have a clue that the apparent patterns are meaningless. In this case, raw numbers would have been far preferable.