• Nonprobability- not every individual as opportunity to be included which increases the chance that sample is not representative of population.
• Convenience sampleis like finding subjects at the right time and place such as an FNP researcher having access to patients with HTN at the clinic where she works which decreases time and expense.
• Quota samplingis creation of strata or categories to include adequate representation of certain groups like women, or people from lower incomes. This increased representation of sample beyond convenience.
• Purposive and snowball samplingare most commonly used inqualitative studieswhere the researcher needs subjects with certain characteristics. Ex .. Women with a perinatal loss.

** Below are key questions to ask when performing a research article appraisal of population, sample and setting:

Population, Sample, & Setting. What was the population for the study? Identify the specific sampling method used for the study.Discuss the adequacy of the sampling method for producing a sample representative of the population.Discuss potential biases with the sampling method used.Identify the inclusion and exclusion criteria used in the study.Discuss appropriateness of the sampling criteria for the study?Discuss how the planned sample size was determined (including power analysis & consideration of potential attrition if included).Discuss actual sample size attained for the study including acceptance rate, refusal rate (including rationale for refusal to participate if presented), and attrition rate.Describe study setting and its appropriateness for the study

Do you notice these key items in research studies related to sampling? Would you think all studies have same types of info?