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Chapter 12
Sampling in Quantitative Research
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Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Question
Tell whether the following statement is true or false:
The aggregate of cases in which a researcher is interested is called a sample.
Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Answer
False
The aggregate of cases in which a researcher is interested is called a population. A sample is selection of a portion of the population to represent the entire population.
Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Basic Sampling Concepts in Quantitative Studies
Population: the aggregate of cases in which a researcher is interested
Sampling: selection of a portion of the population (a sample) to represent the entire population
Element: basic population unit about which information is collected
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Eligibility Criteria
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Question
Tell whether the following statement is true or false:
Researchers usually sample from the target population.
Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Answer
False
Researchers usually sample from the accessible population but should identify the target population to which they want to generalize their results.
Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Basic Sampling Concepts in Quantitative Studies
Representative sample
A sample whose key characteristics closely approximate those of the population
Sampling bias
The systematic over- or underrepresentation of segments of the population on key variables
Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Question
Tell whether the following statement is true or false:
Probability sampling involves random selection of elements.
Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Answer
True
Probability sampling involves random selection of elements.
Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Basic Sampling Concepts in Quantitative Studies (cont.)
Probability sampling
Involves random selection of elements
Nonprobability sampling
Does not involve selection of elements at random
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Nonprobability Sampling
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Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Probability Sampling
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Copyright © 2017 Wolters Kluwer Health | Lippincott Williams & Wilkins
Power Analysis