A researcher posts a radio advertisement offering $35 in exchange for participation in a short study. The researcher accepts the first eight people who respond to the advertisement. Which of the following statements is true about the sample?
It is a valid sample because the first eight people were selected to participate.
It is not a valid sample because it is not a random sample of the population.
It is a valid sample because money was offered to participants.
It is not a valid sample because it is only a short study.
It is not a valid sample because it is not a random sample of the population.
The correct statement is: "It is not a valid sample because it is not a random sample of the population."
To determine if a sample is valid, it is important to consider the methodology used to select participants. In this case, the researcher simply accepted the first eight people who responded to the advertisement. This method, known as convenience sampling, may result in a biased sample, as it does not guarantee that the participants are representative of the population being studied.
For a sample to be considered valid, it is generally recommended to use random sampling techniques. This involves randomly selecting participants from the target population, which helps to ensure that every individual in the population has an equal chance of being included in the study. Random sampling improves the generalizability of the findings from the sample to the larger population.