The 2007–08 administration of SASS consisted of five types of questionnaires: district questionnaires, principal questionnaires, school questionnaires, teacher questionnaires, and school library media center questionnaires. District surveys contained questions on student enrollment, staffing patterns, teacher recruitment, hiring practices, teacher dismissals, salary schedules, school choice, magnet programs, and graduation requirements. Principal surveys collected information about principal demographic characteristics, training, experience, salary, goals and decision making, judgments about the seriousness of school problems, and, new to 2007–08, instructional time, and teacher and school performance. Public and private school surveys obtained information such as grades offered, number of students enrolled, staffing patterns, teaching vacancies, high school graduation rates, programs and services offered, and college application rates. Teacher surveys were designed to measure teachers' education and training, teaching assignment, certification, workload, professional development, perceptions and attitudes about teaching, and income from school and non–school jobs. School library media center surveys were designed to obtain information about the amount and experience of library staff, and the organization, expenditures, and collections of the library media center.
The sampling frame for public traditional and charter schools was built from the 2005–06 Common Core of Data (CCD) school survey, which is a universe survey of all elementary and secondary schools in the United States. Prior to stratification and sampling, the CCD frame was modified extensively to meet the needs of SASS. For example, schools were added and deleted from the CCD in order to fit the definition of a school used in SASS. Schools operated by the Department of Defense or those that offered only kindergarten or prekindergarten or adult education were excluded from the SASS sample. The SASS sample is a stratified probability proportional to size (PSS) sample. All schools, except BIE–funded schools, undergo multiple levels of stratification.
A separate universe of schools operated or funded by the Bureau of Indian Education (BIE) in 2005–06 was drawn from the Program Education Directory maintained by the BIE. [CCD now defines BIE as its own "territory," similar to Puerto Rico and other non–50 state territories, and does not permit duplicates to be reported by the states]. All BIE schools meeting the SASS definition of a school were included in the sample.
The sampling frame for private schools employed a dual frame approach since the list frame does not provide complete coverage. The list frame was based on the 2005–06 Private School Universe Survey (PSS), updated with private school organizations and state lists collected by the Census Bureau in the summer of 2006. An area frame was used to find schools missing from the list frame, thereby compensating for the incomplete coverage of the list frame.
The sampling frame for the teacher questionnaires consisted of lists of teachers provided by sampled schools. The Teacher Listing Form (TLF) was collected as early as possible in the 2007–08 school year at all public (including public charter), private, and BIE–funded schools in the SASS sample to obtain a complete list of all the teachers employed at each school. The sample of teachers was selected from all of the schools that provided teacher lists.
The sample design for the school survey met the objectives for SASS and took into consideration the response burden for schools. The main design objective of the school survey was to provide estimates of school characteristics by the following key analytical domains: the nation; elementary and secondary levels for all sectors; public schools with a population of at least 20 percent American Indian or Alaska Native students; BIE schools at the national level; public schools by school level, region, and state; and private schools by school level, region, and affiliation strata.
Another objective was to balance the requirements of the samples in SASS. For each sampled school, all districts in the public sector, principals, and library media centers in the public and BIE–funded school sectors received questionnaires. The 2007–08 SASS sampled schools first, and then linked each school to its corresponding school district (or local education agency). To obtain a representative teacher sample, schools were more likely to be selected if there were a larger number of teachers within a given school, although schools of all sizes were sampled. Teachers within schools were then sampled at a rate of at least one and no more than 20 teachers per school, averaging between 3 and 8 teachers per school. The SASS sample design also sought to minimize selecting the same schools as other NCES school–based surveys.
The 2007–08 SASS returned to the methodology used in the 1999–2000 SASS, which was a mail–based survey, with telephone and field follow–up. An advance letter was mailed to sampled schools during the summer 2007 to verify school addresses. Subsequently, a package containing all surveys and explanatory information was mailed to sampled schools. Using a computer–assisted telephone–interviewing (CATI) instrument to verify school information, schools were contacted to establish a survey coordinator, and to follow up on the Teacher Listing Form (TLF), which served as the teacher list frame. Sampled teachers were mailed questionnaires on a flow basis. Field follow–up was conducted for schools that had not returned the TLF. Schools were called from Census telephone centers to remind the survey coordinator to have staff complete and return all forms. Individual survey respondents (e.g. principal, librarian, and teachers) were called from the telephone centers to attempt to complete the questionnaire with them over the phone. Field follow–up was conducted for schools and teachers that had not returned their questionnaires.
The U.S. Census Bureau conducted the data processing. Each questionnaire was coded according to its response status—for example, whether the questionnaire contained a completed interview, a respondent refused to complete it, a school district merged with another district, or a school closed. The next step was to make a preliminary determination of each case's interview status, i.e., whether it was an interview, a non–interview, or if the respondent was ineligible for the survey. Information from the CATI instrument was also used to determine the preliminary status of questionnaires, particularly to determine if the school or other respondent was eligible for the survey or not.
Once the data were compiled, a computer program conducted a series of quality control checks, such as range checks, consistency edits, and blanking edits, and generated a list of cases where problems occurred in each survey. After the completion of these checks, the program made a final determination of whether the case was eligible for the survey, and if so, whether there were sufficient data for the case to be classified as an interview. As a result, a final interview status recode value was assigned to each case.
SASS used four methods to impute values for questionnaire items that respondents did not answer. These were: (1) using data from other items on the questionnaire; (2) extracting data from a related component of SASS; (3) extracting data from the sampling frame (CCD or PSS); and (4) extracting data from the record of a sampled case with similar characteristics (commonly known as the "hot deck" method for imputing item response).
Weighting of the sample units was carried out to produce national, regional, and state estimates for public schools, districts, principals, teachers, and school libraries. Private schools, principals, and teachers were weighted to produce national, regional, and affiliation strata estimates. The weighting procedures used in the Schools and Staffing Survey have three purposes: to take into account the school's selection probability; to reduce biases that may result from unit nonresponse; and to make use of available information from external sources to improve the precision of sample estimates.
Weighted response rates are defined as the number of in–scope responding questionnaires divided by the number of in–scope sampled cases, using the base weight (inverse of the probability of selection) of the record. There are two sampling stages for teachers; first, the school–level collection of the Teacher Listing Form (TLF) from sampled schools, and then, sampling of teachers from the TLF. When both stages are multiplied together, the product is the overall weighted response rate. For all other components, only one sampling stage was involved; therefore, for these components, the weighted overall response rate and the weighted response rate are the same.
|SASS sample sizes and base weighted unit and overall response rates: 2007–08|
|Survey population||Sample size||Unit|
|Public School Teacher Listing Form||9,800||86.2||†|
|Private School Teacher Listing Form||2,940||85.1||†|
|BIE School Teacher Listing Form||180||87.3||†|
|Public School District||5,250||87.8||†|
|Public School Principal||9,800||79.4||†|
|Private School Principal||2,940||72.2||†|
|BIE School Principal||180||79.2||†|
|Public School Teacher||47,600||84.0||72.4|
|Private School Teacher||8,230||77.5||65.9|
|BIE School Teacher||750||81.8||71.4|
|Public School Library Media Center||9,800||81.7||†|
|BIE School Library Media Center||180||78.9||†|
|† Not applicable|
|NOTE: The number of sampled public and private school teachers reported in this table differs from that reported in 2007–08 SASS First Look Reports. About 160 public school teachers and 50 private school teachers were sampled from schools that were later determined to be out of scope for SASS.|
|SOURCE: U.S. Department of Education, National Center for Education Statistics, Schools and Staffing Survey, "Public School Teacher, BIE School Teacher, and Private School Teacher Listing Forms, Public School District, Public School, BIE School, Private School, Public School Principal, BIE School Principal, Private School Principal, Public School Teacher, BIE School Teacher, Private School Teacher, Public School Library Media Center and BIE School Library Media Center data files," 2007–08.|
NCES 2009320: Characteristics of Public School Districts in the United States: Results From the 2007–08 Schools and Staffing Survey
NCES 2009321: Characteristics of Public, Private, and Bureau of Indian Education Elementary and Secondary School in the United States: Results From the 2007–08 Schools and Staffing Survey
NCES 2009322: Characteristics of Public and Bureau of Indian Education Elementary and Secondary School Library Media Centers in the United States: Results From the 2007–08 Schools and Staffing Survey
NCES 2009323: Characteristics of Public, Private, and Bureau of Indian Education Elementary and Secondary School Principals in the United States: Results From the 2007–08 Schools and Staffing Survey
NCES 2009324: Characteristics of Public, Private, and Bureau of Indian Education Elementary and Secondary School Teachers in the United States: Results From the 2007–08 Schools and Staffing Survey
NCES 2010332: Documentation for the 2007–08 Schools and Staffing Survey Results (Forthcoming)