Which of the following describes a simple random sample?

A simple random sample is defined as one where every member of the population has an equal chance of being selected. This method ensures that the selection process is impartial and representative of the entire population, which allows for unbiased statistical inferences to be drawn. The randomness in selection helps avoid any potential biases that could arise from selective sampling methods, ensuring that each member's characteristics are equally likely to be represented in the sample. This approach is fundamental in research, as it strengthens the validity of conclusions made about the larger population based on the sample data.

The other options describe different sampling methods. Convenience sampling refers to selecting members based on ease of access rather than random selection, leading to potential biases. Matching specific criteria for selection is indicative of purposive sampling, which focuses on specific characteristics rather than randomness. Choosing members only from focused groups suggests a non-random approach where certain subgroups are prioritized, which can result in skewed data and reduce generalizability. Hence, the answer correctly captures the essence of simple random sampling.