Experiments

Question 1

What is an experiment?

Answer 1

A study where an independent variable is manipulated (or changes naturally) to measure its effect on an operationalised dependent variable

Question 2

What is a lab experiment?

Answer 2

• Take place in an artifical environment
• Have high levels of control
• IV is created by researcher and is manipulated in order to measure effect on DV

Question 3

What are the strengths of lab experiments?

Answer 3

• High levels of control means we can remove extraneous variables. As a result we know that the DV is only affected by the IV. Thus we can be certain of the cause and effect relationship between the IV and DV. This increases validity.
• High levels of control so we can control all variables in the experiment and ensure that they all occur in the same way. This means that we can establish a standardised procedure which means we can repeat the experiment in the same way to check for consistency. This increases reliability.

Question 4

What are the weaknesses of lab experiments?

Answer 4

• As the experiment takes place in an artifical setting, findings aren’t applicable to everyday life. This is because as PPs are in an unfamiliar setting they may display unnatural behaviour that isn’t reflective of their day to day behaviour. Thus it lacks ecological validity
• PPs are generally aware that their behaviour is being measures/assessed. As they are conscious of this they may display unnatural behaviour due to demand characteristics. This decreases validity

Question 5

What is a field experiment?

Answer 5

• Take place in a real life environment
• Limited control
• IV is still manipulated to observe effect on DV

Question 6

What are the strengths of field experiments?

Answer 6

Takes place in a real life setting so PPs are more likely to display natural behaviour compared to those in lab experiments. Findings are applicable to everyday life to help psychologists better understand human behaviour. Thus increasing ecological validity

Question 7

What are the weaknesses of field experiments?

Answer 7

• Lower levels of control than lab experiments so you can’t remove extraneous variables. Therefore we can’t be sure if DV is only affected by IV and so can’t be certain of a cause and effect relationship. Thus decreasing validity
• Lower levels of control than lab experiments so you can’t control all variables to ensure they occur in the same way. Thus can’t establish a standardised procedure meaning we can’t repeat the experiment to test for consistency. This decreases the validity

Question 8

What is a natural experiment?

Answer 8

• Take place in a natural real life setting
• IV occurs naturally and is out of the researcher’s control
• Researcher has no control

Question 9

What is a strength of natural experiments?

Answer 9

Take place in a natural environment meaning findings will be applicable to everyday life. This is because PPs are in a familiar setting and so will display behaviour reflective of their day to day life. Thus increasing ecological validity

Question 10

What are the weaknesses of natural experiments?

Answer 10

• No control means that researcher can’t remove extraneous variables. Therefore we can’t be sure that DV is only affected by the IV. This means that we can’t be certain of a cause and effect relationship thus reducing validity
• No control means we can’t control variables to ensure that they all occur in the same way. Therefore we can’t establish a standardised procedure which means that we can’t repeat the experiment to test for consistency thus reducing reliability.
• Furthermore, random allocation can’t take place as we can’t put people into specific conditions as we have no control.

Question 11

What are quasi experiments?

Answer 11

• Researcher has no control over the IV
• IV is based on existing differences between PPs e.g. male VS female, researcher did not create this difference

Question 12

What is a strength of quasi experiments?

Answer 12

Allows researcher to investigate PP characteristics which may be difficult or unethical to create/cause in an experimemental setting. For example comparing PPs with depression VS PPs without - can’t be considered unethical as researcher didn’t cause this behaviour thus allowing us to study such behaviour

Question 13

What is a weakness of quasi experiments?

Answer 13

As IV is based on PP characteristics, PPs have been naturally allocated to their condition. As a result, researcher can’t randomly allocate PPs into conditions in ordder to control for PP variables. Thus we are less certain that any changes in DV are due to the IV (PP characteristics) or other PP variables. This weakens the cause and effect relationship between the IV and DV thus reducing validity