Research in music education
A "survey" is a systematic method of collecting information on one or more variables. An example of a survey study is a 1998 study by Gillespie and Hamann. The purpose of the study was to gather descriptive information about orchestra programs that can be used as baseline data when considering the needs of school string programs. The findings indicated a continued enrollment increase in school orchestras in the 1990s although the number of orchestra teachers remained stable, and that larger schools are more likely to offer orchestra instruction. The impact of the study was the recommendation that school systems should provide larger, more adequate teaching facilities and that universities and string teachers should emphasize strategies for teaching larger string classes in their teacher preparation programs.
Survey sampling
In a probability sample (also called "scientific" or "random" sample) each member of the target population has a known and non-zero probability of inclusion in the sample. A survey based on a probability sample can in theory produce statistical measurements of the target population that are: 
A probability-based survey sample is created by constructing a list of the target population, called the sampling frame, a randomized process for selecting units from the sample frame, called a selection procedure, and a method of contacting selected units to enable them complete the survey, called a data collection method or mode. For some target populations this process may be easy, for example, sampling the employees of a company by using payroll list. However, in large, disorganized populations simply constructing a suitable sample frame is often a complex and expensive task.