AO1 - Types of Experiments

What is a key characteristic of a laboratory experiment?

• Independent variable cannot be manipulated.
• Researcher directly manipulates the independent variable.
• Participants cannot be randomly allocated.
• Carried out in naturalistic conditions.

A researcher studies how different levels of light affect plant growth in a controlled greenhouse. Based on the scenario, which type of experiment is this most likely?

• Natural experiment
• Laboratory experiment
• Quasi-experiment
• Field experiment

A student claims field experiments are better than lab experiments because they are more realistic. Why might this claim overlook an important benefit of lab experiments?

• Field experiments are not true experiments.
• Realism is not important for experiments.
• Lab experiments allow for better control of outside variables.
• Lab experiments always have more participants.

A researcher is comparing two different therapies for anxiety. They want to ensure that only the therapy itself causes any change in anxiety levels, and not other factors like diet or sleep. To achieve this goal, which experimental characteristic is most important for the researcher to prioritize?

• Direct manipulation of the independent variable.
• Naturalistic conditions.
• Random allocation of participants.
• Careful control of situational extraneous variables.

A psychologist wants to test if a new teaching method improves student test scores. She randomly assigns students in one school to either the new method or the old method. This study is done in the students' regular classrooms. Which type of experiment is the psychologist conducting?

• Laboratory experiment
• Field experiment
• Quasi-experiment
• Natural experiment

A researcher wants to study the effects of a new city policy on public transportation use. They cannot control who is exposed to the policy or randomly assign people to groups. Given these limitations, what might be the most practical approach for the researcher to study the policy's effects?

• Design a quasi-experiment or natural experiment.
• Randomly allocate citizens to receive the new policy.
• Conduct a laboratory experiment with strict controls.
• Manipulate the policy as an independent variable.

Researchers compare the driving habits of people who passed their driving test on the first try versus those who passed on their third try. What challenge do the researchers face in randomly allocating participants to these groups?

• The study is too expensive for random allocation.
• The researchers forgot to include a control group.
• Driving habits are not influenced by past test attempts.
• Passing attempt is an inherent characteristic, making random allocation impossible.

A researcher cannot directly manipulate the independent variable or randomly allocate participants in a study. What does this limitation most strongly imply about the type of experiment being conducted?

• It is a field experiment.
• It is a true experiment.
• It is either a quasi-experiment or a natural experiment.
• It focuses on controlled situational variables.

What makes quasi-experiments and natural experiments different from true experiments?

• They always use independent groups designs.
• They are always conducted in a lab setting.
• The researcher cannot directly manipulate the IV.
• They allow random allocation of participants.

A study compares stress levels in students before and after a major, unexpected exam. Which type of experiment is this an example of?

• Natural experiment
• Quasi-experiment
• Laboratory experiment
• Field experiment