Statistics

Mike the Mad Biologist

Category archives for Statistics

A Handy Transformation for Microbiome Data

When worked on the human microbiome, I regularly confronted a problem with the data. Species frequencies are almost never normally distributed (‘the bell curve’), and if you want to use standard statistical techniques the data should be normally distributed. The second problem is that the data often have a lot of zero values. That is,…

Nicholas Kristof has done some excellent reporting on the issues facing the developing world. But he is a case study in how reporting and analysis are not necessarily part of the same skill set. In Thursday’s column, Kristof writes (italics mine): When I was in college, I majored in political science. But if I were…

Last week, E.D. Kain took Megan McArdle to task for promoting the use of student testing as a means to evaluate teachers. This, to me, was the key point: ….nobody is arguing against tests as a way to measure outcomes. Anti-standardized-tests advocates are arguing against the way tests are being used, and the prioritization of…

For those of you who like interactive data, the American Human Development Project has a great website that drills down to the county level for education, health, and income data in the U.S. It also has all of the data in a spreadsheet, if you want to do your own analysis. So wonk out!

Over at The Art of Science Learning, Peter Economy writes: One of my great concerns for this country’s future is the underperformance of our youth when it comes to achievement in math and science. In December 2010, the Organization for Economic Cooperation and Development (OECD) released the results of its 2009 Program for International Assessment…

By way of Observational Epidemiology, we find an interesting NY Times article by Michael Winerip describing a seventh grade teacher’s experience with value added testing in New York City. I’ll get to value added testing in a bit, but the story also highlights why we need more reporters who have backgrounds in math and science.…

One of the supposed key innovations in educational ‘reform’ is the adoption of value added testing. Basically, students are tested at the start of the school year (or at the end of the previous year) and then at the end of the year. The improvement in scores is supposed to reflect the effect of the…

He might be really good at designing operating systems (or not), but Bill Gates has a slight data problem. In an op-ed arguing that class size is unimportant and that teacher evaluation is crucial–and should be combined with merit pay, Gates makes this blunder (italics mine): Perhaps the most expensive assumption embedded in school budgets…

By way of Bob Somerby, we come across this Brookings Institution report by Tom Loveless, “How Well Are American Students Learning?” There’s a lot in the report, especially since it’s really three studies rolled into one, but part of section I, which debunks the notion that Finland has the best educational system in the world…

Confusing Teachers, Teaching, and Poverty

When I read articles like this and this, it seems that educational ‘reformers’ are dwelling in a world utterly divorced from reality. If teachers unions and their ‘sweetheart deals’ are the problem, then why does Massachusetts excel? The teachers unions are very strong, and teachers are well compensated. For that matter, if teachers are so…