Selection bias is a type of error that occurs when the sample of individuals or items that are studied is not representative of the broader population. This can happen when the individuals or items are selected in a way that is not random, or when certain groups are underrepresented or overrepresented in the sample. Selection bias can lead to incorrect conclusions and can affect the validity of research findings. To avoid selection bias, it is important to ensure that the sample is selected in a way that is random and representative of the broader population. This can be done through methods such as random sampling, stratified sampling, or cluster sampling.
