Which sampling method involves subjects that are easy to reach, such as friends and classmates?

Convenience sampling is the method that involves selecting subjects who are easily accessible, which often includes friends, classmates, or anyone readily available to the researcher. This approach is characterized by its practicality and efficiency, allowing researchers to gather data quickly without the need for a more structured approach to sampling.

The primary advantage of convenience sampling is that it saves time and resources, making it a common choice in situations where rapid data collection is needed. However, this method can lead to biased results because it does not represent the larger population accurately. The sample may reflect the traits or opinions of a specific group, which limits the generalizability of the findings.

In contrast, random sampling involves selecting subjects randomly from the entire population, ensuring that every individual has an equal chance of being included. Systematic sampling requires selecting subjects at predetermined intervals from a list, while stratified sampling involves dividing the population into subgroups and sampling from each to ensure representation across key characteristics.

Thus, convenience sampling is distinct in its focus on ease of access to subjects rather than on random selection or representation, making it the correct answer in this scenario.