NAEP Assessment Sample Design → NAEP 2011 Sample Design → Sample Design for the 2011 National Assessment → 2011 Writing Computer-Based Assessment (WCBA) → Public School 2011 Writing Computer-Based Assessment (WCBA)

NAEP Technical DocumentationPublic School 2011 Writing Computer-Based Assessment (WCBA)

			Target Population Sampling Frame Stratification of Schools Sampling of Schools Substitute Schools Ineligible Schools Student Sample Selection

The NAEP 2011 writing computer-based assessment (WCBA) sample design yielded nationally representative samples of public school students in each grade (grades 8 and 12) through a three-stage approach: selection of primary sampling units (PSUs), selection of schools within strata, and selection of students within schools. The sample of schools was selected with probability proportional to a measure of size based on the estimated grade enrollment in the schools.

The 2011 WCBA was administered in both grades 8 and 12, with the goal of assessing 19,800 students in each grade. The target sample size was adjusted to reflect expected public school and student response and eligibility.

Schools on the sampling frame were explicitly stratified prior to sampling by PSU type (certainty/noncertainty). Within certainty PSUs, schools were implicitly stratified by census region, urban-centric locale and median household income in the zip code area where the school is located. Within noncertainty PSUs, schools were implicitly stratified by PSU stratum, urban-centric locale, and median income in the zip code area where the school is located. 

From the stratified frame of public schools, systematic random samples of eighth- and twelfth-grade schools were drawn with probability proportional to a measure of size based on the estimated grade enrollment of the school, in the relevant grade.  

Each selected school in the public school samples provided a list of eligible enrolled students from which a systematic, equal probability sample of students was drawn.

Printer-friendly Version