The sample design for the 2009 science hands-on tasks (HOT) and science interactive computer tests (ICT) assessments provided a nationally representative sample of fourth-, eighth-, and twelfth-grade students.
This was accomplished by designing separate sample components for public and private schools. The selected samples were based on a three-stage sample design:
The samples of schools were selected with probability proportional to a measure of size based on the estimated fourth-, eighth-, and twelfth-grade enrollment in the schools.
The target population respectively included all students in public and private schools, Bureau of Indian Education (BIE) schools and Department of Defense Education Activity (DoDEA) schools, who were enrolled in the fourth, eighth, and twelfth grade at the time of assessment.
The table below shows the target student sample sizes of assessed students for each sample.
School type | Grade | Assessment |
|
---|---|---|---|
Science HOT | Science ICT | ||
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2009 National Science Assessment. | |||
Public | 4, 8, 12 | 1,800 | 1,800 |
Private | 4, 8, 12 | 200 | 200 |
To reduce the burden on any particular school, efforts were made to minimize the overlap of the 2009 science sample PSUs with the PSUs selected for the 2008 arts sample and the 2008 long-term trend sample.