The following is a Guest Post by Stephanie Zvan of Almost Diamonds.BackgroundOn February 26, Anonymous Coward at Bayblab suggested that popular ScienceBloggers like PZ Myers (Pharyngula) needed more science content in order to be counted as a science blog. In the first comment on that post, DrugMonkey pointed out that there was plenty of science on Pharyngula, and the matter rested there (sort of, once the author proclaimed the post only an experiment).Then, on May 12, rommy told PZ Myers (in a comment on Pharyngula), “Sorry PZ – I have long thought that your blog was one of the weaker science ones – too much ranting not enough science – go take some lessons off Darren at Tetrapod Zoology on how to write a science blog.”Obviously, the question of whether Pharyngula is a science blog needed to be settled. Greg issued the challenge and I, because I am a complete geek who can’t walk away from piles of data when it might answer a question, took it on.Sorting the PostsI chose five blogs to look at. Pharyngula had to be included, of course, and Greg suggested he be as well. rommy held up Tetrapod Zoology as an example of a blog that was doing everything right. Bayblab pointed to Cognitive Daily as another. And it only seemed fair to include Bayblab as well. In the interest of full disclosure, I read Pharyngula, Greg’s blog, and Cognitive Daily regularly. Cognitive Daily was my gateway drug for ScienceBlogs. I’ve read Tetrapod Zoology and Bayblab occasionally if I’ve seen a link to a post that looked interesting.I picked February, the shortest month, to make my life easier. The effect was somewhat mitigated by this being a leap year. I made no attempt to determine whether February was a typical blogging month for any of the bloggers I chose.Because I wanted to know what people were talking about in more detail than whether they were talking about science, politics, science politics or something else, I expanded on Greg’s suggested categories. I ended up with eight. Brief descriptions are included below. If a post’s content was mixed, the higher category on this list prevailed. I made no attempt to grade the posts on amount, depth or quality of information included.Post CategoriesOriginal Science Content: Summaries of current knowledge, presentations of the blogger’s research, definition and discussion of terms.Other Science Content: Blogging on Peer-Reviewed Research, reporting and linking to research results, announcing future research projects, links to educational essays or videos.History of Science: Who discovered what and when.A Life in Science: Life as a scientist.Politics of Science: Controlling what is funded and taught.Other Politics: Not directly science-related.Blogkeeping: Meta-blogging, blogrolls, requests for information, links to interesting blog posts, promoting and reporting on the blogger’s appearances on the web and in person.General: Other items that strike the fancy or the nerve of the blogger.Not that inclusion in a category such as Blogkeeping or General does not mean that the post was not full of geekery that would appeal to scientists and science fans. Also, events, interviews and podcasts promoted by the bloggers frequently contained science content that wasn’t counted for this study because it was not on the blogger’s own site.Results and DiscussionWhat did I learn? Greg posts a lot. Well, okay, I knew that already, but categorizing 310 posts for a single, short month is still painful. Pharyngula boasted just over half that many at 175, with Bayblab at 43, Cognitive Daily at 17 and Tetrapod Zoology at 16.Aside from that? How much science content you see on each blog depends on how much you limit your definition of science content. If you only include Original Science Content, Tetrapod Zoology is your winner, with Pharyngula and Cognitive Daily suffering by comparison. Add Other Science Content, however, and Greg pulls away from the pack, while the other four even out somewhat.Add the other science-related categories, and Greg and PZ make the others look like total slugabeds. (Yes, that’s a technical term.)So it would seem that the real burden of the complaint is not so much that Pharyngula doesn’t contain enough science, but rather that it contains too much other stuff. While I don’t know that “too much” was within the scope of my assignment, Pharyngula, Greg’s blog and Bayblab do contain much higher percentages of non-science content than Tetrapod Zoology and Cognitive Daily.Again, please note that much of what is labeled here as non-science may still hold special appeal for science fans. Additionally, at least on ScienceBlogs, readers may use feeds that exclude much of the non-science content.ConclusionsOnce again, we discover that there are differences between bloggers. What hasn’t been borne out is the idea that writing about things other than science requires that there be less science content in a blog. In fact, prolific science bloggers tend to blog prolifically about science as well.There are two questions I’d still like to see addressed: Why is diversity among bloggers a bad thing to some people, and who thinks that telling a blogger what to write is productive?