Week 6
Notes before class
Sampling is the process of selecting representative units of a population for study in a research investigation.
To obtain the experiences or outcomes of engaging in this education, the researcher needs to select the appropriate sampling strategy in accordance with the research design and question. This is done to avoid erroneous conclusions or making generalizations from a nonrepresentative sample
A population is a well-defined set that has certain specified properties or characteristics from which data can be gathered and analyzed. A population can be composed of people, animals, objects, or events.
For example, if a researcher is studying undergraduate nursing students, the type of educational preparation of the population must be specified. In this example, the population consists of undergraduate students enrolled in a generic baccalaureate nursing program.
A population may be broadly defined and potentially involve millions of people, or it may be narrowly specified to include only a few people. The target population is the entire population of interest (everyone with breast cancer), while the accessible population is the portion of the target population that is available to the researcher (everyone with breast cancer that lives in the area, like from Princess Margaret Hospital). (textbook, pg 279)
As much as possible, the researcher must specifically delineate the exact criteria used to decide whether an individual would be classified as a member of a given population.
Consider the population previously defined as undergraduate nursing students enrolled in a generic baccalaureate program. Would this population include both part-time and full-time students? Would it include students who had previously attended another nursing program? What about international students? At which level (first year through senior year) would students qualify?
The population descriptors that provide the basis for inclusion (eligibility) criteria should be evident in the sample; in other words, the characteristics of the population and the sample should be congruent. The degree of congruence is evaluated to assess the representativeness of the sample
For example, if a population is defined as full-time, Canadian-born, senior-level nursing students enrolled in a generic baccalaureate nursing program, the sample would be expected to reflect these characteristics.
Inclusion criteria, or eligibility criteria- characteristics of a population that meet requirements for inclusion in a study