Exam 4: Data Collection and Sampling

The larger the sample size is, the more accurate we can expect our sample estimates to be.

A pharmaceutical company interested in measuring how often physicians prescribe a certain drug has selected a simple random sample from each of two groups: M.D. (Medical Doctors)and D.O. (Osteopaths). What is this type of sampling called?

When the population is divided into mutually exclusive sets, and then a simple random sample is drawn from each set, this is called:

Gender, occupation, and age are all examples of ____________________ variables.

In designing a survey, demographic questions must be avoided.

A self-selected sample is one in which the individuals choose themselves to be in the sample.

Self-administered surveys usually have a high response rate.

____________________ sampling is particularly useful when it is difficult or costly to develop a complete list of the population members.

Give an example of a poll that involves a self-selected sample.

Describe the difference between an observational study and an experimental study.

Briefly discuss three methods of conducting a survey of people.

A researcher conducts a study where she divides subjects into two groups, gives each group a certain treatment, and records their responses. What type of data collection is being used here?

A marketing research firm selects a random sample of adults and asks them a list of questions regarding their beverage preferences. What type of data collection is involved here?

Briefly describe three types of nonsampling errors.

A simple random sample is chosen in such a fashion that every possible subset of the same size has an equal chance of being selected.

The target population is the population about which we want to draw inferences and conclusions, while the sampled population is the actual population from which the sample has been taken.

Selection bias is a systematic tendency to favor including individuals with particular characteristics, while excluding individuals with other characteristics.

Pollsters want to know what percentage of all registered voters in Missoula, Montana, intend to vote in the next election. They visit with 350 people at the downtown shopping mall during one afternoon and ask each person whether or not they intend to vote. Are the target population and the sampled population the same in this case? Explain.

Which of the following is an example of a nonsampling error?

Is it possible for a sample to yield better results than a census, from a practical standpoint? Explain.