Question

Research involves measurement scales, of which there are four types. In data collection, what sources of data would you use, and how would you establish reliability and validity? Why did you choose those specific data samples?

Answer 1

In research, there are many different types of variables used. In the case of scales of measurements, there are four types; nominal, ordinal, interval, and ratio. With data collection, “There are a variety of strategies available to collect data. Common data collection strategies include observation, rating scales, permanent products, and anecdotal notes. A good researcher collects data using multiple strategies, because it is through the process of evaluating a situation from multiple perspectives that he or she gathers more accurate information.” From this, I would gather information from multiple avenues and to ensure the accuracy and reliability of the information. There are two different data sources you can pull from, primary data and secondary data.

It is a concern every time a single observer is the source of data, because we have no certain
guard against the impact of that observer’s subjectivity [Babbie, 2010]. Reliability issues are
most of the time closely associated with subjectivity, and once a researcher adopts a subjective
approach towards the study, then the level of reliability of the work is going to be compromised
[Wilson, 2010].
The coefficient of reliability falls between 0 and 1, with perfect reliability equaling 1, and no
reliability equaling 0. The test-retest and alternate forms are usually calculated reliability by
using statistical tests of correlation [Traub & Rowley, 1991]. For high-stakes settings (e.g.,
licensure examination) reliability should be greater than 0.9, whereas for less important
situations values of 0.8 or 0.7 may be acceptable. The general rule is that reliability greater than
0.8 are considered as high [Downing, 2004].
Reliability is used to evaluate the stability of measures administered at different times to the
same individuals and the equivalence of sets of items from the same test [Kimberlin &
Winterstein, 2008]. The better the reliability is perform, the more accurate the results; which
increases the chance of making correct decision in research. Reliability is a necessary, but not a
sufficient condition for the validity of research.

  In research, validity has two essential parts: a) internal (credibility), and b) external
(transferability). Internal validity indicates whether the results of the study are legitimate because of the way the groups were selected, data were recorded or analyses were performed. It refers to
whether a study can be replicated [Willis, 2007]. To assure it, the researcher can describe
appropriate strategies, such as triangulation, prolonged contact, member checks, saturation,
reflexivity, and peer review. External validity shows whether the results given by the study are
transferable to other groups of interest [Last, 2001]. A researcher can increase external validity
by: i) achieving representation of the population through strategies, such as, random selection, ii)
using heterogeneous groups, iii) using non-reactive measures, and iv) using precise description to
allow for study replication or replicate study across different populations, settings, etc.
It alarmed with weather a researcher measures the right concept or not [Shekharan & Bougie,
2010]. Validity requires that an instrument is reliable, but an instrument can be reliable without
being valid [Kimberlin & Winterstein, 2008].