Why is it difficult to obtain a representative sample?

Obtaining a representative sample is challenging because it requires capturing the diversity and characteristics of the entire population while avoiding biases. Factors such as accessibility, response rates, and selection methods can lead to overrepresentation or underrepresentation of certain groups. Additionally, practical constraints like time, resources, and logistical issues often limit the ability to gather a truly representative sample. These challenges can result in skewed data that may not accurately reflect the population's attributes.