REVIEW THE VOCAB:
Types of Samples from a Population
When taking a survey, the population is the group of people about whom the information is to be gathered. For example, if you wanted to conduct a survey about what foods to serve in the cafeteria, the population would be the entire student body. Since it is not usually convenient to survey the total population, different kinds of samples may be used.
A representative sample is a subgroup of the population that matches the general characteristics of the entire population. If you choose to sample 10% of the students, you would need to include an equivalent fraction of students from each grade and an equivalent ratio of male to female students as the larger population.
A convenience sample is a subgroup of the population where it is easy to collect data. Only sampling the students in your homeroom, for example, would be convenient, but would not necessarily accurately represent the entire school.
A cluster sample is a subgroup of the population that contains a common characteristic. Sampling only the eighth graders, in the above example, would be a cluster sample. Again, this sample would not necessarily represent the entire school.
A voluntary response sample contains only the sample of the population that chose to respond. This also would not necessarily represent the entire population.
