ACT (Enhanced)ScienceHard
A research team is investigating the genetic diversity of a population of endangered butterflies. They decide to collect butterflies from a single large, easily accessible meadow, assuming it represents the entire population. However, the endangered species is known to inhabit several geographically distinct areas with varying vegetation types. What type of methodological flaw is most likely to affect their results?
- AObserver bias
- BSelection bias
- CConfirmation bias
- DSampling bias
Show answer & explanationAnswer & explanation
Correct answer: D. Sampling bias
By collecting butterflies from only one easily accessible meadow, the researchers are not obtaining a representative sample of the entire population, which is distributed across various habitats. This non-random or unrepresentative selection of participants or data points is known as sampling bias.
Why the other options are wrong
- A. Observer bias occurs when a researcher's expectations or beliefs influence their observations or measurements.
- B. Selection bias is a broader term that encompasses sampling bias but also includes issues like self-selection in studies. While sampling bias is a form of selection bias, 'sampling bias' is more specific and accurate for this scenario of unrepresentative data collection from a natural population.
- C. Confirmation bias involves interpreting new evidence as confirmation of one's existing beliefs or theories.
Sampling Bias
A bias in which a sample is collected in such a way that some members of the intended population are less likely to be included than others.
- Leads to a non-representative sample.
- Can result in inaccurate conclusions about the total population.
- Often arises from convenience sampling or incomplete sampling frames.
Memory trick: Bad samples skew the truth.