A researcher wants to gather data on the average wing strength of all birds found in the American Northwest. The researcher only has one small net, so all large birds were excluded from the study. The researcher’s results were different than expected, but he believes his data include enough birds to estimate the strength of all birds. For which of the following reasons should this data be rejected?
A.
Data contradict the control group
B.
Data were different than expected
C.
Data are biased by the methodology
D.
Data cannot be displayed graphically
The Correct answer and Explanation is:
The correct answer is C. Data are biased by the methodology.
Explanation
The researcher’s data should be rejected primarily because the data are biased by the methodology. In this study, the researcher used a small net that excluded all large birds. This exclusion introduces a significant bias into the data, as it does not accurately represent the entire population of birds in the American Northwest.
Methodological Bias: The primary issue here is that the method of data collection—using a small net that only captures smaller birds—creates a non-representative sample of the bird population. By excluding all large birds, the sample is skewed and does not reflect the average wing strength of all birds in the region. Since large birds, which were excluded, might have different wing strength characteristics compared to smaller birds, the data collected cannot be used to estimate the average wing strength of all birds accurately.
Impact on Results: The exclusion of a significant portion of the bird population (large birds) results in data that is not comprehensive. This methodology prevents the researcher from obtaining a true average wing strength for all birds in the American Northwest. Consequently, any conclusions drawn from this biased data will be misleading and incorrect. The researcher’s belief that the data are sufficient to estimate the strength of all birds is flawed because the sample does not include a crucial segment of the population.
Comparison with Other Options:
- A. Data contradict the control group: This option is not applicable here as there is no mention of a control group in the study, and the issue lies with sampling bias rather than contradiction with a control group.
- B. Data were different than expected: While unexpected results might indicate a problem, the primary issue in this scenario is the methodological bias rather than the unexpected nature of the results.
- D. Data cannot be displayed graphically: The inability to display data graphically does not inherently invalidate the data. The problem here is the representativeness of the data rather than its graphical representation.
In summary, the data are biased due to the exclusion of large birds, which compromises the study’s validity and accuracy in estimating the average wing strength of all birds in the region.