What is meant by 'sample bias'?

Sample bias refers to a situation where the sample selected for a study does not accurately represent the characteristics of the larger population that the researchers are interested in studying. This can occur for various reasons, such as the method of selection or the inherent characteristics of the sample group. When sample bias is present, the findings of the study may not be generalizable to the population as a whole, leading to distorted or misleading conclusions.

The other options describe different concepts. The first option describes an ideal scenario where the sample does represent the population. The third option refers to methods of sampling rather than to bias itself. Finally, the last choice discusses techniques to ensure diversity in samples, which can help mitigate bias rather than defining it. Thus, recognizing sample bias is crucial for ensuring the validity and reliability of research findings.