Sampling Bias Statistics Example 1
Follow the full solution, then compare it with the other examples linked below.
Example 1
easyA school wants to know whether students prefer longer lunch breaks. They survey students in the cafeteria at lunchtime. Identify the sampling bias.
Solution
- 1 Step 1: The population of interest is all students in the school.
- 2 Step 2: By surveying only students in the cafeteria, they miss students who eat elsewhere (classroom, outside, skip lunch). This is a convenience sample.
- 3 Step 3: Students in the cafeteria may have stronger opinions about lunch because they actively use the lunch period, making the sample biased toward students who value lunchtime.
Answer
The sampling bias is that only students in the cafeteria are surveyed, excluding those who eat elsewhere. This convenience sample may over-represent students who care about lunch breaks.
Sampling bias occurs when some members of the population are more likely to be selected than others. Convenience sampling — surveying whoever is easiest to reach — is a common source of bias that can produce results that do not represent the whole population.
About Sampling Bias
Sampling bias occurs when a sample is collected in a way that systematically makes some members of the population more likely to be included than others, producing results that do not accurately represent the full population and leading to misleading conclusions.
Learn more about Sampling Bias →More Sampling Bias Examples
Example 2 medium
A website runs an online poll asking 'Should the government raise taxes?' and 90% of respondents say
Example 3 mediumA researcher wants to estimate the average income of adults in a city. She interviews people at a sh
Example 4 hardIn the 1936 US presidential election, the Literary Digest magazine polled 2.4 million people and pre