What happens to the representativeness of a sample when attrition occurs during a study?

When attrition occurs during a study, it generally reduces the representativeness of the sample. Attrition refers to participants dropping out of a study, which can lead to a situation where the remaining participants may not accurately reflect the original population from which they were drawn.

This change is significant because the characteristics of those who remain in the study may differ from those who left. For example, if individuals with specific traits or responses are more likely to drop out, the final sample might skew towards the remaining individuals, leading to bias in the findings. As a result, the conclusions drawn from the study may not be generalizable to the larger population, thereby impacting the validity of the research outcome. In essence, when participants leave the study, the diversity and variability of the data can be compromised, thus diminishing the study's overall robustness and applicability to the intended population.