Our guest author today is William Schmidt, a University Distinguished Professor and co-director of the Education Policy Center at Michigan State University. He is also a member of the Shanker Institute board of directors.
Every year or two, the mass media is full of stories on the latest iterations of one of the two major international large scale assessments, the Trends in International Mathematics and Science Study (TIMSS) and the Program for International Student Assessment (PISA). What perplexes many is that the results of these two tests -- both well-established and run by respectable, experienced organizations -- suggest different conclusions about the state of U.S. mathematics education. Generally speaking, U.S. students do better on the TIMSS and poorly on the PISA, relative to their peers in other nations. Depending on their personal preferences, policy advocates can simply choose whichever test result is convenient to press their argument, leaving the general public without clear guidance.
Now, in one sense, the differences between the tests are more apparent than real. One reason why the U.S. ranks better on the TIMSS than the PISA is that the two tests sample students from different sets of countries. The PISA has many more wealthy countries, whose students tend to do better – hence, the U.S.’s lower ranking. It turns out that when looking at only the countries that participated in both the TIMSS and the PISA we find similar country rankings. There are also some differences in statistical sampling, but these are fairly minor.