Showing posts with label box and whisker plots. Show all posts
Showing posts with label box and whisker plots. Show all posts

Tuesday, March 16, 2010

Box plots

So I am in the process of putting together a manuscript my lab has been working on over the course of the past few months. We've done a lot of quantitative PCR to get at an integral question about an environment we've (the royal 'we') been interested in for years. So, the first order of business I do is put together all my figures and tables. The tables were easy peasy, and most of the figures were too. I've come to the qPCR data however and I had a couple of options. I could do the data as tables or I could do figures. The journal I'm sending the manuscript to has no problem with an excess of tables (I've seen manuscripts with up to nine tables and no figures) but I don't like them.

Now, if you look at a lot of qPCR manuscripts, people use columns, which I suppose is fine because you'll see the mean and standard deviation ... but you also lose a lot of data. I mean, say your Y axis goes from 1 to 100, and the mean goes to 65. You know, probably for a fact, that you didn't have a reading of 0, or 1, or 2 ... but there is that area ... shaded out as a part of your column. Not really accurate, right?

So I've become enamored with box and whisker plots. They really do give you more information than your traditional columns graph. Just take a look at the figure below as an example.

Which one gives you more information?


Now, there are ways to make the box and whisker plot even more descriptive (I'm using the Analyze It! plug-in for Excel), but on the face of it, I think the box and whisker plots are a great tool for presenting qPCR data. So I looked to see who presents their data that way ... and almost no one does.

So, what am I missing here? Is it really a good way to present qPCR data, or isn't it? If it is, why isn't anyone else doing it? If not, what is the best way to present the data?