IB Psychology HL : Introduction to experimental research methodology

Study concepts, example questions & explanations for IB Psychology HL

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Example Questions

Example Question #1 : Simple Experimental Study

What is the main benefit of choosing a large sample for a study (as opposed to a smaller one)?

Possible Answers:

It is more likely to be representative of the population

It is guaranteed to be representative of the population

It is less time consuming

It is less difficult to coordinate

It is less costly

Correct answer:

It is more likely to be representative of the population

Explanation:

The ideal sample that is chosen out of a population is a representative sample, which means that the makeup of the sample generally matches the makeup of the population. The main benefit of choosing a larger sample is that it is more likely to be representative of the population; however, unless the sample includes the entire population (which it rarely, rarely does), it does not guarantee that it will be representative. However, larger samples are often more time consuming, harder to coordinate, and more costly, so those drawbacks have to be balanced.

Example Question #2 : Simple Experimental Study

A researcher is curious about how temperature relates to aggression and predicts that as the temperature in a room increases, a measure of the subject's aggression will increase as well. What is the experimental design term for "aggression" in this scenario?

Possible Answers:

Dependent variable


Hypothesis

Independent variable

Theory

None of these

Correct answer:

Dependent variable


Explanation:

A variable is described something that varies between people or objects—in this case, temperature and aggression are the variables. The “independent variable” (IV) is the variable that is manipulated by the researcher (temperature) and the “dependent variable” (DV) is the variable that changes as a result of a change in the IV (aggression). A “hypothesis” describes the relationship between variables and is generally what the researcher predicts will happen (i.e. “as the temperature in a room increases, a measure of the subject's aggression will increase as well”). Last, a “theory” is a principle or set of principles that explains a phenomenon.

Example Question #3 : Simple Experimental Study

What is the main benefit of choosing a large sample for a study (as opposed to a smaller one)?

Possible Answers:

It is guaranteed to be representative of the population

It is more likely to be representative of the population

It is less time consuming

It is less difficult to coordinate

It is less costly

Correct answer:

It is more likely to be representative of the population

Explanation:

The ideal sample that is chosen out of a population is a representative sample, which means that the makeup of the sample generally matches the makeup of the population. The main benefit of choosing a larger sample is that it is more likely to be representative of the population; however, unless the sample includes the entire population (which it rarely, rarely does), it does not guarantee that it will be representative. However, larger samples are often more time consuming, harder to coordinate, and more costly, so those drawbacks have to be balanced.

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