In systematic sampling, how is the sample selected?

Systematic sampling involves selecting members of a population at regular intervals from a predetermined list. This process starts with a random selection of a starting point, and then every nth individual is chosen from that point onward. The methodology ensures that the sample is spread evenly across the population, which can help reduce bias.

For instance, if a researcher has a list of 100 individuals and decides to select every 10th person, they might begin with a randomly chosen individual, say the 4th one, and then select the 14th, 24th, and so on. This structured approach allows for a systematic representation of the population.

Other options do not accurately describe systematic sampling; however, they represent different sampling techniques. Random selection from a group describes simple random sampling, while choosing individuals based on personal connections pertains to purposive or convenience sampling. Finally, selecting based on availability aligns with convenience sampling, which prioritizes ease over a systematic approach. Each of these methods differs from the regular interval selection that characterizes systematic sampling, highlighting its unique structure and intent.