# Specific Types of Quantitative Research & Sampling in Quantitative Research.

Chapter 12

Sampling in Quantitative Research

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Question

Tell whether the following statement is true or false:

The aggregate of cases in which a researcher is interested is called a sample.

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.

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

• Establish population characteristics
• Determine participation in study
• Maximize construct validity
• Inclusion
• Exclusion

Question

Tell whether the following statement is true or false:

Researchers usually sample from the target population.

False

Researchers usually sample from the accessible population but should identify the target population to which they want to generalize their results.

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

Question

Tell whether the following statement is true or false:

Probability sampling involves random selection of elements.

True

Probability sampling involves random selection of elements.

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

• Convenience sampling
• Snowball sampling
• Quota sampling
• Consecutive sampling
• Purposive sampling

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Probability Sampling

• Simple random sampling
• Stratified random sampling
• Multistage sampling
• Cluster sampling
• Systematic sampling

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