Scarlett Is a Graduate Student Who Is Observing Children Playing

question 129

Multiple Choice

Scarlett is a graduate student who is observing children playing together after watching a film.She knows that some children saw a film that contained graphic scenes of violence and some children saw a non-violent film,but she doesn't know which film each child she is observing watched.In this case,Scarlett is recording data for

• A) a double-blind research study.
• B) a study with two independent variables.
• C) an unethical research study.
• D) a correlational study with confounded variables.

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Definitions:

E(X + Y)

The expected value of the sum of two random variables, equal to the sum of their individual expected values.

Covariance

A measure that indicates the extent to which two variables change together, but does not indicate the strength of their relationship.

Independent

Not influenced by or dependent on another variable; in statistics, it often means that the occurrence of one event does not affect the probability of another event.

COV(X,Y)

Covariance between two variables X and Y, measuring the extent to which the variables change together and indicating the direction of their linear relationship.