What does selection bias refer to in research?

Selection bias refers to a situation in research where the sample chosen for a study does not accurately represent the larger population from which it is drawn. This discrepancy can lead to skewed results and conclusions that are not generalizable. When the study sample is not representative, certain groups may be overrepresented or underrepresented, which can affect the validity and reliability of the findings. Accurate representation is crucial for the integrity of any research, as it ensures that the results can be effectively applied to the broader context.

Choosing a random sample is a method used to avoid selection bias; however, if the sampling is not executed properly, it can still result in non-representative samples. The influence of personal opinions or a tendency to select only favorable results can contribute to bias but are not the defining characteristic of selection bias itself.