If you haven’t found Seth’s Blog, I highly recommend it!  Seth Roberts, Ph.D., is a professor emeritus of psychology at the University of California at Berkeley.  He writes about a variety of topic, but has a great mind for statistics.  He often posts about statistics that are used incorrectly, by people who are usually considered experts in the field.  By reading about the incorrect uses and his related explanations, I am reminded to be wary of what I read, and it sharpens my ability to read research.

I particularly enjoyed a recent post titled “‘Baffling’ Link between Autism and Vinyl Floors”.  In fact I loved it so much that I sent the link to all of my nerdy statistics loving friends.  At first, it seems like an amazing break through… Scientific America writes that:

“Children who live in homes with vinyl floors, which can emit chemicals called phthalates, are more likely to have autism, according to research by Swedish and U.S. scientists published Monday.

The study of Swedish children is among the first to find an apparent connection between an environmental chemical and autism.”

Wow!  What a break though, right?  Maybe, but maybe not.  Seth points out some real weaknesses in the study’s methodology, including the often incorrect assumption that a large sample size is both necessary, and the most important aspect of research design.

So if you took statistics or research methods years ago, this is a great reminder about sound research methodology, and that even journals as prominent as Scientific America sometimes don’t get it 100% correct.

My brother-in-law showed me a website that he knew I would appreciate, not so much for it’s content, but for the impressive data display.  I was skeptical, but once I started clicking through the presentation, I was hooked!  The display of data was so interactive and compelling, that I kept clicking until the display was finished.  It’s called Gapminder.  Click here to see it for yourself!

I immediately started thinking about all the ways I would love to use such a data display for educational research.  Here are two topics that I read recently that I would love to see presented using Gapminder:

In the Public Education Weekly NewsBlast (June 13, 2008):

SCHOOL SIZE NOT KEY TO SMALL HIGH SCHOOL SUCCESS, STUDY FINDS
A new study by Education Resource Strategies, “Strategic Designs: Lessons for Leading Edge Small Urban High Schools,” examines nine high-performing small urban high schools throughout the country to better understand how they achieved their success. The report by Karen Hawley Miles and Regis Shields finds that the success of small urban high schools rests less on their smaller size and more on how they use their resources strategically. The high-performing schools in the study — all schools with flexibility over their resources — proactively manage people, time, and money, and demonstrate that it’s not just how much money is spent that impacts student learning, but how well resources are used.
http://www.educationresourcestrategies.org/small_schools.htm

In Eduwonkette (June 15, 2008)

In a new paper, “The Persistence of Teacher-Induced Learning Gains“, Brian Jacob, Lars Lefgren, and David Sims estimate how much of the teacher effect fades out over time. It turns out that kids lose more of these short-term test score gains that we (or at least I) thought:
“Our estimates suggest that only about one-fifth of the test score gain from a high value-added teacher remains after a single year. Given our standard errors, we can rule out one-year persistence rates above one-third. After two years, about one-eighth of the original gain persists.”

If you have the courage and interest to try using this on your own, the software has been bought by google (i love google!)  and is free for you to use.  Their first output is now up and running as a free Google Gadget called Motion Chart. It allows evryone to make a gapminder-like bubble graph that you can publish on your web-page or blog.   » Read more about Motion Chart…