fundamental in any type of research. The two aspects of quality in research are
reliability and validity. There are types of measures used to assure that the
study is reliable and valid. Sampling pertains to the determination of the who
and what should be included in the research. These are the subjects who will be
observed, interviewed, or tested during the study. There are attributes that constitute trustworthiness
or rigor of a research such as credibility, transferability, dependability, and
confirmability. There are two case study samples that are reviewed in terms of
its sampling, reliability, validity and trustworthiness.
Reliability, Validity and Trustworthiness
Part of the planning phase of
research is to aim at sampling, reliability, validity, and trustworthiness in
research. The benchmarks are established to assure reliability and validity of
a research study. These terms are further defined to understand their
differences and purposes as applied during research process. One important goal
in research is to introduce randomness and prevent application of a system that
could include biases.
A Case Study Review on Sampling,
Reliability and Validity
are two major types of sampling: qualitative sampling and quantitative
sampling. There are sub-types under each type. Sampling consists of who and
what to be included in the test. There are two general questions that must be
addressed prior to selecting your required samples: the size and the
composition (Tappen, 2016). Sampling is also defined as the process of finding
a representative of a chosen population for the intention of establishing
parameters or attributes of the entire population (Robert, 2015). There are
certain terminologies that are constantly used in research sampling which must
be identified and understood beforehand (Harvey, 2012-17). First is population. It is defined as the group
of people a researcher is interested in including in the study. Second is parameter. It is defined as characteristic
of a certain variable regarding the population. Third is sampling frame. It is the list of the entire population the
researcher is interested in. Fourth is sample.
It is the subgroup of people from a sampling frame or population. Fifth is representative. It refers to the sample
that has the same attributes of the population. Sixth is generalizable. It is the ability to generalize the data to the
population. Seventh is sampling error.
It is the difference between a parameter and a statistic.
probability sampling and non-probability sampling are two types of quantitative
Sampling. Non-probability sampling is like convenience sampling but non-generalizable.
On the other hand, convenience sampling, purposeful sampling, and theoretical
sampling are types of qualitative sampling. Convenience sampling is the least
scientific and lacks intellectual credibility. Theoretical sampling is based on
grounded theory which is more discriminant.
Sample Case: Stress Management for Patients with Rheumatoid Arthritis
Rigor in Qualitative Research
must be ascertained in any type of research. Quality is fundamental. Rigor is referred
to the compliance to the quality standards in conducting research to increase
the assurance in the results. To assure rigor in research, the method in
answering the intended research question must be appropriately addressed and
the chosen research design must be strong. Researchers believe that without
proper rigor, a research is bound to be no worth. Therefore, there must be a
general criteria or quality measured standards in evaluating research studies. Rigor
in research is attributed to the trustworthiness of the research.
Trustworthiness in qualitative research describes four basic elements:
credibility, transferability, dependability, and confirmability (Tappen, 2016).
described by R. Tappen (2016), credibility is identical to internal validity
which can be accomplished through five different ways. First, is by having enough
time to persistently engage, observe, and test for possible reason and outcome.
Second, is by reviewing and sharing your raw notation, interview transcripts or
preliminary outcomes to your participants or representatives of the people you are
working with to gain input or feedback from them and later include those
feedbacks in your conclusion. Third, is by including feedback from experts in
that particular study: methodology or subject. An objective critiquing of a
study takes time and interest on the part of the expert but can yield a
trustworthy result. Fourth, is by providing and considering other possible explanations
on participants’ negative viewpoints or data. The existence of the negative
cases must not be ignored and must be analyzed and reported regardless of its
impact. Fifth, is by referencing or cross checking two or more data to provide wider
perspectives that can be valuable in your complex study.
as noted by R. Tappen (2016), is parallel to external validity. In quantitative
research, transferability refers to how findings are applicable to other people
and situations thus can be generalized. Dependability, which is similar to reliability,
can be achieved by creating an audit trail while research is underway. Audit
trail covers a recorded compilation of your notes, researcher’s thought process
and reflections, survey guides, data, and including decisions during the study.
Confirmability as R. Tappen (2016) describes is the objectivity specifically in
quantitative research. The inclusion of a reflexive journal, which includes recorded
expectations and ideas prior to the study, which can support a researcher as
reference while answering his research questions.