A pilot study represents a cornerstone of a good research
design. In fact, a pilot study is an essential initial step in
a research and this applies to all types of research studies.
The term of pilot study, however, is defined as “a smallscale
test of the methods and procedures to be used on a
large scale …” (Porta 2008). On the other hand, there is
little published guidance with respect to the sample size
required for pilot studies. The study of Billingham et al.
(2013) mentioned that even though all studies should have a
sample size justification, some kinds of studies do not need
to have a sample size calculation. Their studies, however,
concluded that a formal sample size calculation for pilot
studies may not be appropriate. Generally, 10–20% of the
main sample size is a reasonable number for conducting a
pilot study (Baker 1994). ectors including
marketing, and financial business sectors