Question

Alan is conducting a survey to find out the type of art preferred by students at the town’s high school. Identify the population of his survey and describe a possible sample of the population.

Answer 1

Explanation:

Non-probability sampling:

Finding a suitable group of respondents to finish the survey is more common than using probability samples in many surveys. Non-probability sampling instances that are frequently used include:

• Samples were chosen based on judgment: A researcher uses his or her judgment to choose which individuals of the population to include in the sample. For the sample's representativeness, the researcher may offer an alternative justification. The underlying presumption is that the researcher will pick units that represent the population as a whole. This approach is susceptible to the prejudices and perspectives of the researcher.
• When a target population is uncommon, snowball samples are frequently used. Other members of the population are recruited for the survey by members of the target population.
• Quota Samples: The sample is intended to comprise a specific number of individuals who meet particular criteria. 100 coffee drinkers, as an example. Non-probability market research surveys frequently use this kind of sampling.
• Convenience Samples: The sample is made up of whoever can be contacted the easiest to complete the survey.
• The link between the survey sample and the target population is impossible to measure with non-probability samples, and any potential bias is unknown. Instead of using the survey as a tool to evaluate the population, sophisticated users of non-probability survey samples often regard it as an experimental condition and review the data for internal consistency.

Probability sampling:

• Each member of the target population has a known and non-zero probability of being included in the sample when using a probability sample, also known as a "scientific" or "random" sample. Theoretically, a survey using a probability sample could result in statistical measurements of the target population that are: unbiased; the expected value of the sample mean is equal to the population mean and have a quantifiable sampling error, which can be expressed as a confidence interval, or margin of error.
• A sampling frame, also known as the target population, a selection procedure, also known as the random process for selecting units from the sample frame, and a data collection method or mode, also known as the method of contacting selected units to enable them to complete the survey, are used to create a probability-based survey sample. This technique might be simple for some target populations, such as when sampling a company's employees utilising payroll lists. However, creating a proper sample frame is sometimes a difficult and expensive task in big, disordered populations.
• Area Probability Sampling, Random Digit Dial Telephone Sampling, and more recently Address-Based Sampling are common ways to undertake a probability sample of the household population in the United States.