What Is a Sample?
The sample is the group of elements, or a single element, from which data are obtained. Although the phrase “the sample included used to indicate the characteristics of the people or events in the ple, the nature of the sampling procedure is usually described by one or more adjectives, such as random sampling or stratified random sampling. These types of sampling procedures are defined, with illustrations from actual studies, in the following section. It is important for the researcher to define as specifically as possible both the sampling procedure and the characteristics of the sample used in the study. Here is an example of a good description of the sample.
this study consisted of
district brochure, the district had
in 42 elementary schools, 9 middle schools, and 9 high schools during
the school year the study was conducted.
and their students. All teachers had and each teacher received a 5100 stipend. The
p u b l i c s c h o o l s i n a m e d i u m - s i z e d W e s t e r n c i t y , a l o w - m i d d l e t o m i d d l e
community with a
proportion of minorities.
:; :$ ,t
sizes ranged from 16 to 34.
There’were 5 femb?
teachers. The teachers had an average of approximately 11 years of
teaching experience (range
teachers (range 2
2-26). Of these 11 years, 8 were as math 6 were as middle-school math teachers
2-10). All had secondary
and 4 had Master’s de-,
in Administration. One of the teachers had a
major in college,
6 a math minor, and 2 had no special training in math.”
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TYPES OF SAMPLING PROCEDURES
The purpose of sampling is to obtain a group of subjects who will be representative of the larger population or will provide specific informa-
tion needed. The degree of
is based on the sampling
technique employed. I and then consider the
will first strengths
describe different and weaknesses of
sampling each in
procedures obtaining a
In social science and educational research it is usually impractical and unnecessary to measure all the elements in the population of interest.
Typically, a relatively small number of subjects or
is selected from
Sample: Group of subjects from
whom data are collected.