What is sample and why sampling method is used?

What is sample

A sample is a subset, or some part, of a larger whole. A larger whole could be anything out which
sample is taken. That ‘whole’ could be a bucket of water, a bag of sugar, a group of organizations, a
group of students, a group of customers, or a group mid-level managers in an organization. A complete
group of entities sharing some common set of characteristics is population. In other words, the totality
out of which sample is drawn is referred to as population.
Why sample?

1. Saves Cost, Labor, and Time

Applied research projects usually have budget and time constraints. Since sample can save financial cost
as well as time, therefore, to go for sample study is pragmatic.
Of course, a researcher investigating a population with an extremely small number of population
elements may elect to conduct a study on the total population rather than a sample because cost, labor,
and time constraints are relatively insignificant.
Although sample study cuts costs, reduces labor requirements, and gathers vital information quickly, yet
there could be other reasons.

2. Quality Management/supervision

Professional fieldworkers are a scarce commodity. In a large study rather than employing less qualified
staff it may be advisable to do a sample study and employ highly qualified professional fieldworkers. It
can certainly affect the quality of the study. At the same time it may be easier to manage a small group
and produce quality information. Supervision, record keeping, training, and so forth would all be more
difficult in a very large study.
3. Accurate and Reliable Results

3. Accurate and Reliable Results
Another major reason for sampling is that samples, if properly selected, are sufficiently accurate in most
of the cases.

4. Sampling may be the Only Way

Many research projects, especially those in quality control testing, require the destruction of the items
being tested. If the manufacturer of firecrackers wished to find out whether each product met a specific

5. Determine the Period of Study

Interviewing every element of a large population without sampling requires lot of time, may be a year or
more. In such a long period study, even the seasonal variation may influence the response pattern of the
respondents. For example, if the study was aimed at measuring the level of unemployment in a given
large city, the unemployment rate produced by the survey data would not refer to the city as of the
beginning of interviewing or as of the end. Researcher may be forced to attribute the unemployment to
some