Dr. Parrett is a sports psychologist for a large Southern university. The provost and chancellor have asked him to examine the relationship between athletic performance and academic stress at the university. For example, is it the case that the most talented athletes experience the greatest concern over their grades? The provost and chancellor have made it clear to Dr. Parrett that they want a large amount of external validity in the study. He has valid and reliable measures of both athletic performance and academic stress. He knows that he does not have the time or the money to study the entire population of interest.

1. What is the population of interest in Dr. Parrett’s study? (1 point)

2. Why does he need to be concerned with external validity/representativeness? (2 points)

3. Describe how Dr. Parrett could conduct the following types of sampling:

a. Convenience sample (1 point)

b. Simple random sample (1 point)

c. Cluster sample (1 point)

4. Of each of the sampling techniques above, which one do you think would lead to the most representative sample and why? (2 points)

Extra Credit (2 points)

How do you think they measure concern over their grades? Is this likely a self-report measure or observational measure and why do you think so?

The answers to the questions are;

1. Athletes within the campus.

2. Usefulness of the research.

3. Pulling the representative student athlete of each of the sampling methods.

4. Simple random sample.

Observational measure.

Step-by-step explanation:

1, Athletes he can reach more specifically, those within his psychology lecture classes and those athletes within the campus especially  those representing various types of sports  

2 External Validity and representativeness are important as

External validity has to do with the generalization of results. It indicates the level of confidence of applying internally generated conclusions to external situations. That is if the results of the research can be accepted on a larger scale or population

Representatativeness concerns the relationship between the sample selected and the population of interest. It indictes the level of accuracy of the findings concerning the topic of interest. A representative study is able to obtain the correct orientation of a population from sample data of the population

3 a. Convenience sample

Here, Dr Parret collects the sample data based on easily accessible sources such as requesting the required information from athletic students in his classes or visiting hostels hosting only athletes to distribute questionnaires

b.  Simple random sample

Here, Dr Parret seeks out athletic students present within the university without focusing on a particular subset. He can do this by taking sample data from athletes at sporting events.

c. Cluster sample

Here, Dr Parret splits the entire athletic population into clusters or groups then he randomly selects the cluster upon which the sample data is to be based. For example, clusters could be in the type of sporting activity the athlete is engaged in. Thereby he might choose baseball athletes to be the source of the sampled data.

4. Simple random sample would lead to the most representative sample because it is the most unbiased form of sampling that cuts across individual athlete engagement

They measure concern over their grades mainly by observational measure as they are also engaged in sporting activities of which some are likely to have a higher comparative advantage.