Mean of Purposive sampling,
Cluster sampling,
Simple Random Quota sampling Voluntial
sampling Voluntary Sampling
Stratified sampling Captive
sampling Accidental
sampling Systematic sampling
Purposive sampling: Also known as judgmental, selective or subjective
sampling is a type of non-probability sampling technique.
Non-probability sampling focuses on sampling techniques where the units
that are investigated are based on the judgment of the researcher. There
are a number of different goals.
Cluster sampling: is a sampling technique used when “natural” but
relative heterogeneous groupings are evident in a statistical
population. It is often used in marketing research. In this technique,
the total population is divided into these groups (or Clusters) and a
sample random sample of the groups is selected. The elements in each
cluster are sampled, and then this is referred to as a “one-stage”
cluster design.
Systematic sampling: is a statistical method involving the selection of
elements from an ordered sampling frame. The most common form of
systematic sampling is an equal-probability method. In this approach,
progression through the list is treated circularly, with a return to the
top once the end of the list is passed.
Accidental sampling: is a type of non- probability sampling that
involves the sample being drawn from that part of the population that is
close to hand. That is, sample populations selected because it is
readily available and convenient, as researchers are drawing on
relationships or networks to which they have easy access. The researcher
using such a sample cannot scientifically make generalizations about
the total population from this sample because it would not be
representative enough. For example, if the interviewer was to conduct
such a survey at a shopping center early in the Moring on a given day,
the people that he/she could interview would be limited to those given
there at that given time, which would not represent the views of other
members of society in such an area, if the survey was to be conducted at
different times of day and several times per week.
Captive sampling: it comparison of 2 behavioral sampling method to
establish a time budget in a captive female cheetah (Acinonyx jubatus)
Behavioral studies of wild animals kept in captivity useful information
for conservation programs and animal welfare.
Stratified sampling: is a method of sampling from a population. In
statistical survey, when subpopulations within an overall population
vary, it is advantageous to sample each subpopulation (stratum)
independently. Example: Assume that we need to estimate average number
of votes for each candidate in an election. Assume that country has
three (3) towns: Town A has 1 million factory workers, Town B has 2
million office workers, and Town C has 3 million retirees. We can choose
to get a random sample of size 60 over entire population but there is
some chance that the random sample turns out to be not well balanced
across these town and hence is biased causing a significant error in
estimation. Instead if we choose to take a random sample of 10, 20 and
30 from Town A, B and C respectively then we can produce a smaller error
in estimation for the same total size of sample.
Voluntial sampling: Voluntary Sampling is one of the main types of
non-probability sampling method. A voluntary sampling is made up of
people who self-select into the survey. Often, these folks have a strong
interest in the main topic of the survey. Suppose, for example, that a
news show asks viewers to participate sample. The sample is chose by the
viewers, not by the survey administrator.
Quota sampling: is a method for selecting survey participants that is a
non-probabilistic version of stratified sampling. In quota sampling, a
population is first segmented into mutually exclusive sub-groups, just
as in stratified sampling. Then judgment is used to select the subjects
or units from each segment based on a specified proportion. Example: an
interviewer may be told to sample 200 females and 300 males between the
age of 45 and 60. This means that individuals can put a demand on who
they want to sample (targeting) the second step makes the technique non-
probability sample.
Simple Random: in statistics, a simple random sample is a subset of
individuals (a sample) chosen from a larger set (a population). Each
individual is chose randomly and entirely by chance, such that each
individual has the same probability of being chosen at any stage during
the sampling process, and each subset of k individuals has the same
probability of being chosen for the sample as any other subset of K
individual. A simple Random sample is an unbiased surveying
technique.






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