Final answer:
A self-selected sample formed by individuals responding to a general appeal for participation is not reliable because it may introduce bias and doesn't guarantee that the sample accurately represents the population. Random sampling is preferred as it gives everyone an equal chance of selection, enhancing the representativeness and reliability of the research.
Step-by-step explanation:
The statement 'The sample chooses itself by responding to a general appeal for participation' refers to a self-selected sample, which is often not reliable. This is because self-selected samples only include responses from people who choose to respond, such as in the case of internet surveys. This selection method can introduce bias, as those who choose to participate may have different opinions or characteristics than those who do not.
Furthermore, a large sample size does not necessarily ensure reliability if the sample is self-selected. It is essential for the sample to represent the broader population adequately. That's why random sampling is more effective, as it gives every person an equal chance of being chosen for the study, which can help provide more accurate results that reflect the public opinion or characteristics of the entire population.
In summary, while self-selection is a quick and easy way to gather a sample, it doesn't guarantee the representativeness needed for reliable research findings.