How bias can impact sampling techniques
Explain how bias can impact sampling techniques. Describe how researcher bias during sampling can influence results, outcomes, and analysis of data.
Sample Solution
How Bias Can Impact Sampling Techniques
Bias in sampling techniques can occur when the researcher selects a sample that is not representative of the population of interest. This can happen for a variety of reasons, such as:
- Convenience sampling: Convenience sampling is a non-probabilistic sampling method in which the researcher selects the most accessible or convenient sample members. This type of sampling is often used because it is quick and easy, but it is also highly susceptible to bias. For example, a researcher who is studying student attitudes towards a new course might recruit participants from the first class they meet with. This sample would not be representative of all students at the university, as it would be biased towards students who are enrolled in that particular course.
Full Answer Section
- Self-selection sampling: Self-selection sampling is a non-probabilistic sampling method in which sample members volunteer to participate in the study. This type of sampling is also highly susceptible to bias, as it is only likely to attract people who are interested in the topic of the study. For example, a researcher who is studying the effects of a new drug on weight loss might recruit participants from a weight loss forum. This sample would not be representative of all people who are overweight or obese, as it would be biased towards people who are already motivated to lose weight.
- Nonresponse bias: Nonresponse bias occurs when some sample members choose not to participate in the study. This can happen for a variety of reasons, such as lack of interest, time constraints, or concerns about privacy. Nonresponse bias can lead to a biased sample if the nonrespondents are systematically different from the respondents. For example, a researcher who is studying the effects of a new drug on smoking cessation might recruit participants from a smoking clinic. If more non-smokers than smokers choose to participate in the study, the sample will be biased towards non-smokers.
- A researcher who is studying the effects of a new drug on depression might recruit participants from a support group for people with depression. This sample would be biased towards people who have severe depression, and the results of the study would not be generalizable to the general population.
- A researcher who is studying the effects of a new educational program on student achievement might recruit participants from a school in a wealthy neighborhood. This sample would be biased towards students from high-income families, and the results of the study would not be generalizable to all students.
- A researcher who is studying the effects of a new social media platform on adolescent mental health might recruit participants from a social media platform that is popular among adolescents. This sample would be biased towards adolescents who are already active on social media, and the results of the study would not be generalizable to all adolescents.
- Using probabilistic sampling methods: Probabilistic sampling methods are methods in which every member of the population has a known probability of being selected in the sample. This helps to ensure that the sample is representative of the population.
- Stratifying the sample: Stratification is a method of dividing the population into subgroups and then sampling from each subgroup. This helps to ensure that all subgroups are represented in the sample.
- Weighting the sample: Weighting is a method of adjusting the data from a sample to make it more representative of the population. This can be done by giving more weight to data from subgroups that are underrepresented in the sample.