What Are the Purposes of Completing a Pilot Study

What are the purposes of completing a pilot study?

A) It provides nominal and ordinal data with which the researcher can construct better instruments.
B) It helps identify problems the researcher might encounter while collecting data.
C) It justifies the existence of a research gap.
D) It gives the researcher preliminary data to present the institutional review board in order to obtain permission to conduct research.
E) It provides an idea of the time lines of the proposed study, including instrument-completion and subject recruitment.