According to Wu & Thompson (2020), sampling theory refers to the principles that guide the drawing of samples from a given population to use them in making inferences. Sampling theory illustrates that study samples should accurately represent the population from which they are drawn. According to the sampling theory, a population refers to the entire group about which a researcher wants to make conclusions while a sample refers to the specifically selected group from which data is collected. The various methods of sampling include probability where every member of a given population has a chance of being selected and non-probability which uses a non-random criterion where some individuals in a population do not have a chance to be selected in a study sample. Sampling theory is widely applicable such as in studies aiming at identifying the mean heights of individuals in a given area of management writing help.
In nursing research, generalizability is used to measure the usefulness of the outcome of research to the entire populace. According to Leung, (2017), generalizability in nursing qualitative research studies is assessed by adopting similar validity measures such as system sampling, constant comparison and triangulation, and correct audit and certification. Additionally, researchers also utilize analytical generalizability to measure the degree to which the results of a study can be generalized into another one in a comparable circumstance and theoretical considerations.