Health Services Research (HSR) Methods
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The process of selecting and observing individual units in order to make statistical inferences or make conclusions about the population.

The proportion of subjects in a population selected for analysis is called the sampling fraction.


A study is designed to estimate the prevalence of substance abuse among adults in City A. To obtain a representative sample of adults, iinvetigators used a random number table to identify a random subset of individuals in a list of telephone numbers.

Further Reading
Gliner, J.A. and G.A. Morgan. 2000. Research Methods in Applied Settings, Mahwah, NJ: Lawrence Erlbaum Associates.

Last, J. 1983. A Dictionary of Epidemiology, New York, NY: Oxford Medical Publications.

Schutt, R.K. 2006. Investigating the Social World - The Process and Practice of Research, Thousand Oaks, CA: SAGE Publications.