Final answer:
The preferred method for selecting sampling sites is through a random process to ensure an unbiased and representative sample of the population. A non-random selection can lead to a biased sample and does not accurately represent the community. Random sampling includes methods such as simple random sampling, stratified sampling, cluster sampling, and systematic sampling.
Step-by-step explanation:
The preferred method for the selection of sites for sampling is a random process where each member of the population has an equal chance of being selected. This method ensures that the sample is unbiased and representative of the broader community. A convenient sample, where the researcher selects members of the community intentionally, can introduce bias. Random sampling includes different types, such as simple random sampling, stratified sampling, cluster sampling, and systematic sampling.
To be more specific, solution 1.23 clearly indicates that not selecting areas at random leads to a biased sample. Therefore, random selection is essential to avoid claims that a non-random sample represents the community. Additionally, according to exercise 7, choosing a random sample is an effective method because everyone has the same chance of being part of the study, which avoids control by the researcher over who is included, thus minimizing selection bias.