Define sampling. Discuss the different methods of sampling
Sampling
Researchers usually can not make direct observation of every individual in the
population under study. Instead, they collect data from a subset of individuals
a sample – and use those observations to make inferences about the entire
population. Ideally, the sample corresponds to the larger population on the
characteristics of (s) of interest. In that case, the researcher’s conclusions from
the samples are properly applicable to the entire population. Sampling is the
process of selection of units (e.g. people, organisation) from a population of
interest so that by studying the sample may fairly generate results back to the
population from which they were chosen.
SAMPLING METHODS
Non Probability Sampling Methods
Non probability sampling is one is which there is no way of assessing the
probability of the element or group of elements, of population being included
in the sample. In other words, non-probability sampling methods are those
that provide no basis for estimating how closely the characteristics of sample
approximate the parameters of population from which the sample had been
obtained
Probability Sampling
Probability sampling methods are those that clearly specify the probability or
likelihood of inclusion of each element or individual in the sample. Probability
sampling is free of bias in selecting sample units. They help in estimation of
sampling errors and evaluate sample results in terms of their precision,
accuracy and efficiency and hence, the conclusions reached from such samples
are worth generalisation and comparable to similar population to which they
belong
IMPORTANCE OF SAMPLING
In research, sampling method has obtained great importance. Sampling studies
are becoming more and more popular in all type of studies. The vastness of the
population, the difficulties of contacting people, high refusal rate, difficulties of
ascertaining the universe make sampling the best alternative in case of social
studies. The census method is rarely, if ever tried in matters of social research.
Recent developments in sampling technique have made this method more
reliable and valid. The results of sampling have attained a sufficiently high
standard of accuracy. The three main advantage of sampling are that cost in
lowest, data collection is faster, and since the data set is smaller, it is possible to
ensure homogeneity and to improve the accuracy and quality of data (Ader,
Mellenbergh & Hard (2008)
