Effectiveness of a Composite Size Measure for Sampling Students with Disabilities

• Activity Number: 413
• Type: Contributed
• Date/Time: Tuesday, July 31, 2012 : 2:00 PM to 3:50 PM
• Sponsor: Section on Survey Research Methods
• Author(s): Frank Potter*+
• Companies: Mathematica Policy Research
• Keywords: Sample Design ; Disabilities ; School Survey ; Rare Populations

Abstract

Rare and hard-to-reach populations pose significant challenges to the design and implementation of cost-efficient sample surveys. To find and enumerate these populations, multi-stage surveys are often used to avoid the construction of a sampling frame for the entire target population, and primary sampling units (PSUs) are selected with probability proportional to a size measure related to the population sizes in the PSUs. When multiple populations are of interest, composite size measures are used that are based on the population counts in the PSUs to achieve equal or nearly equal selection rates within the populations. Some composite size measures were described by Folsom, Potter and Williams (1987) and by Fahimi and Judkins (1991). The purpose of this paper is to identify the capabilities and limitations of using a composite size measure for a survey of students with disabilities in which some disabilities are prevalent and some are very rare. The paper will provide guidance on when the use of composite size measure achieves the desired objectives and when it cannot.