The student sample selection within sampled schools for the national main assessment was systematically drawn from school-prepared lists of eligible students. Ineligible students were those who had been deemed by school officials to be unable
to participate meaningfully in the assessment or
to be unable to participate without assessment accommodations that the program did not, at the time, make available.
These ineligible students; therefore, were excluded from the assessment. Student listing forms (SLF) were prepared for each participating school in a given grade; all enrolled students of the specified grade were to be entered on the SLFs. Student samples also included oversampling of Black and Hispanic students in low minority public schools, and oversampling SD/LEP students in all schools. The samples were specified through the use of session assignment forms.
There were a number of schools, primarily in the Southwest, which are year-round schools, where at any given time a certain percentage of the students will be on vacation. At the time of assessment, a certain percentage of students were off track—in their out-of-school period. Assignment to tracks was generally a random process; the sample design treated the on-site students as an equal probability sample from the full set of grade-eligible students. In the assessed sample, there were 11 fourth-grade schools in this category, three eighth-grade schools, and two twelfth-grade schools. The percentages of off-track students in these schools ranged from a low of 25 percent to a high of 33 percent.