Research and Statistical Method: Sample Size, Sampling Method, Reliability, Control Variables, and Research Design

This article discusses the selection of appropriate sample size, sampling method, reliability, control variables, and research design in research and statistical method. It covers the formula for minimum sample size, justification for larger sample size, advantages and disadvantages of simple random sampling, reliability and validity issues of quantitative job insecurity, qualitative job insecurity, and psychological distress, importance of control variables, and advantages and disadvantages of correlational research design.

RESEARCH AND STATISTICAL METHOD
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Question 1
In selection of appropriate sample size, a tradeoff exists owing to higher accuracy of a larger
sample versus a lower cost of a lower sample. The relevant factors for determining the
minimum sample size are the accuracy desired by researcher (captured as Margin of Error)
along with population standard deviation (σ) which highlights the underlying heterogeneity in
population. The formula for minimum sample size is given below (Eriksson & Kovalainen,
2015).
For the given case study, a larger sample of about 21% of population is justified owing to
heterogeneity in population owing to demographic parameters that would impact the
responses of the participants (Flick, 2015).
Question 2
Since for each sample, the selection of employees is without any classification based on
gender, education or level, therefore the sampling method used in this research study is
simple random sampling (Hair et. al., 2015).
Advantages:
1) It is easy to use and economical to perform
2) Does not require any theoretical knowledge about sampling
3) Classification errors do not exist
Disadvantages:
1) The sample obtained may not be representative of the population since the key
attributes such as gender, age may not be in the proportion as witnessed in the
population since employees have not been classified based on these key attributes
(Hillier, 2016).
Question 3

 Quantitative job insecurity– Reliability is acceptable since cronbach’s alpha is greater
than 0.8. Validity issues also would not arise since measure has been deployed in
previous study with comparable context (Flick, 2015).
 Qualitative job insecurity – Reliability is acceptable since cronbach’s alpha is greater
than 0.7. Validity issues would arise owing to selective use of 10 measures out of 17
which can lead to results that are not valid (Hillier, 2016).
 Psychological distress – Reliability is acceptable since cronbach’s alpha is greater
than 0.7. Validity issues would arise owing to questionnaire being more than five
decades old and hence may not capture the reality pertaining to modern work
environment and related stresses (Hair et. al., 2015).
Question 4
The various variable i.e. age, gender and education level have been used as control variables
considering the change in any of these variables can bring about a change in the qualitative or
quantitative measures of job insecurity. These are kept constant by the researcher so that any
association that is observed between the quantitative and qualitative measures is not
influenced by these parameters (Hair et. al., 2015). These factors are pivotal as individuals
differing according to gender, education and age tend to have different expectations of
priorities due to which the impact of qualitative and quantitative factors would vary (Eriksson
& Kovalainen, 2015).
Question 5
The research design used for the given study is correlational (Flick, 2015).
Advantages:
1) High amount of data collection since broader focus as compared to other research
designs
2) Provides preliminary association trends between variables which then can be studied
in depth based on other research designs.

3) Lead to theory building since it provides hypothesis which can be tested using
experimental or descriptive research designs.
Disadvantages:
1) Indicate only association between variables but do not explain the underlying causes
2) It can be carried out for two variables at a time.

References
Eriksson, P. & Kovalainen, A. (2015) Quantitative methods in business research (3rd ed.).
London: Sage Publications.
Flick, U. (2015) Introducing research methodology: A beginner's guide to doing a research
project (4th ed.). New York: Sage Publications.
Hair, J. F., Wolfinbarger, M., Money, A. H., Samouel, P., & Page, M. J. (2015) Essentials of
business research methods (2nd ed.). New York: Routledge.
Hillier, F. (2016) Introduction to Operations Research (6th ed.). New York: McGraw Hill
Publications.