DQ 2 : Describe sampling theory and provide examples to illustrate your definition.

Sampling theory is the claim that a properly drawn subset can stand in for a population, and the word doing the work is properly. Define the target population, the accessible population and the sample as three distinct things, because the gap between the first two is where most nursing studies lose their external validity long before anyone worries about sample size. Then illustrate with contrasting techniques rather than a list: simple random sampling gives every member a known and equal chance and supports inference; stratified sampling protects subgroups that random draw would under-represent; convenience sampling, which is what most master's-level nursing projects actually use, gives you the nurses who were on shift and no basis at all for saying the sample resembles anyone else. Naming the technique you would genuinely use, rather than the one you would prefer, is what makes the second half of this post honest.

Generalisability in nursing research is the more interesting half because the honest answer is often that it is limited, and saying so is a strength rather than an admission. A fall-prevention bundle tested on one thirty-bed medical unit in one urban teaching hospital does not automatically transfer to a rural critical access hospital with a different staffing model and case mix. The professional move is to describe the sample and setting in enough detail that a reader elsewhere can judge the fit for themselves — sometimes called transferability, and it puts the burden on reporting rather than on statistics. Distinguish that from statistical generalisation, which needs probability sampling you probably do not have. Then connect it back to your own project: state what your accessible population is, what it excludes, and which readers could reasonably act on your result. A limitations paragraph naming one specific excluded group beats a general disclaimer about small samples.