The fourth survey in this series is the NAEP, the National Assessment of Educational Programs. Goal here? And this is, by now internationally, we know a lot of surveys of this kind. Pisa, Tims study. They all try to measure math and reading skills. And this one here applies a uniform measurement across the states in the US. In order to facilitate comparison of schools of states, and a measurement of change. The target population for this particular survey is 4th, 8th, 12th graders in U.S. schools. It, again, is a multi-stage area probability sample, so similar to what we had before, with about 100,000 students in 2,000 schools. You can already see how the data structure that emerged here is a erect structure. And definitely want where it's worthwhile checking out our course on survey data analysis. In order to make sure that you know how to properly report and estimate results, from this kind of data structure. Again, this is a repeated cross sectional survey, meaning the cases are selected into the survey, interviewed, and then released, and not followed up. So no panel survey in this case. It's a computer-based assessment, administered by field workers at the individual schools. The questionnaire itself looks a little different, in part because this piece here is a test question for the students. You see the correct answers here as well. Those of course the students would not see. If you wanna take a look at this assessment test, you can do so at the NCES website. Again, some graphs here, different in the average scores for 12th grade math assessment, by private, public, and Catholic schools in the US. The time span reported here is about 10 years, and now we could add another 10, or soon even 20 to this. NAEP Design Issues. In general, this is the hope, to assess effects on teaching targets, and a measurement of students' language performances. A little bit of an issue with these measurements. If you try to measure math skills and they require you to read and write your results, then of course that's somewhat confounded with English level skills. There's a political oversight to this highly contentious data. A lot of people move according to quality of school districts, and housing prices follow along. So that's an important thing to keep in mind.