Kumar-2011-Research-Methodology_-A-Step-by-Step-Guide-for-Beginners

Chapter 12: Selecting a sample 213
a predetermined sample size and the saturation point distinguishes their use in quantitative
and qualitative research.
2 In quantitative research you are guided by your desire to select a random sample, whereas in
qualitative research you are guided by your judgement as to who is likely to provide you with
the ‘best’ information.
The concept of saturation point in qualitative research
As you already know, in qualitative research data is usually collected to a point where you are
not getting new information or it is negligible – the data saturation point. This stage determines
the sample size.
It is important for you to keep in mind that the concept of data saturation point is highly
subjective. It is you who are collecting the data and decide when you have attained the saturation
point in your data collection. How soon you reach the saturation point depends upon
how diverse is the situation or phenomenon that you are studying. The greater the diversity,
the greater the number of people from whom you need to collect the information to reach
the saturation point.
The concept of saturation point is more applicable to situations where you are collecting
information on a one-to-one basis. Where the information is collected in a collective format
such as focus groups, community forums or panel discussions, you strive to gather as diverse
and as much information as possible. When no new information is emerging it is assumed that
you have reached the saturation point.
Summary
In this chapter you have learnt about sampling, the process of selecting a few elements from
a sampling population. Sampling, in a way, is a trade-off between accuracy and resources.
Through sampling you make an estimate about the information of interest. You do not find the
true population mean.
Two opposing philosophies underpin the selection of sampling units in quantitative and
qualitative research. In quantitative studies a sample is supposed to be selected in such a way
that it represents the study population, which is achieved through randomisation. However,
the selection of a sample in qualitative research is guided by your judgement as to who is likely
to provide you with complete and diverse information. This is a non-random process.
Sample size does not occupy a significant place in qualitative research and it is determined
by the data saturation point while collecting data instead of being fixed in advance.
In quantitative research, sampling is guided by three principles, one of which is that the
greater the sample size, the more accurate the estimate of the true population mean, given
that everything else remains the same. The inferences drawn from a sample can be affected
by both the size of the sample and the extent of variation in the sampling population.