4.2.3 EXPERIMENTAL METHOD

Question 1

what is a lab experiment?

Answer 1

laboratory experiment

• the researcher has high levels of control over all of the variables within the experiment
• the researcher is able to control the environmental factors
  -> like noise and temp
  -> they can control the experiences of the participants and make sure that all participants have exactly the same instructions
• the procedure will be standardised to allow for this control
• the experimenter will make sure all variables within the experimental space are kept the same and only the independent variable, the one they want to measure, changes between conditions
• this allows the experiment to measure the dependent variable clearly within the experiment

Question 2

what are three strengths of the lab experiment?

Answer 2

1) it’s easier to replicate a laboratory experiment
-> this is because a standardised procedure is used
-> increases reliability

2) high internal validity is achieved as the independent validity may be seen to affect the dependent variable

3) cause and effect conclusions are more possible than other methods due to the control the researcher is able to exert
-> precise control of extraneous and independent variables

Question 3

what are three limitations of the lab experiment?

Answer 3

1) artificiality of the setting may produce unnatural behaviour that doesn’t reflect real life
-> low ecological validaty
-> meaning it wouldn’t be possible to generalise the findings to a real life setting

2) demand characteristics or experimenter effects may bias the results and become confounding variables
-> as ppts know they are in a study so may alter their behaviour which impairs the validity of the study

3) often lacks mundane realism meaning the results cannot be generalised to real-world behaviour

Question 4

what is a field experiment?

Answer 4

• the experiment is conducted in a naturalistic setting
  (real life, everyday setting) eg) a supermarket, a school
• an independent variable is manipulated by the researcher (as in laboratory experiments) but not in a lab setting
• the dependent variable is measured quantitatively as in laboratory experiments

Question 5

what’s three strengths of the field experiment?

Answer 5

1) behaviour in a field experiment is more likely to reflect real life because of its natural setting
-> higher ecological validity than a lab experiment

2) there’s less likelihood of demand characteristics affecting the results as ppts may not know they’re being studied
-> this occurs when the study is covert

3) high levels of mundane realism, which means the results are more likely to be able to be generalised to real-world behaviours

Question 6

what are two limitations of the field experiment?

Answer 6

1) there’s less control over extraneous variables that might bias the results
-> makes it difficult for another researcher to replicate the study in
exactly the same way
-> could change the measurement of the DV

2) harder to assign ppts and so means it’s more likely a change could happen due to ppt variables, rather than what the researcher is measuring

Question 7

what’s a natural experiment?

Answer 7

• the researcher doesn’t manipulate the independent variable to measure the outcome
  -> takes advantage of the naturally occurring IV (would’ve occurred whether the experimenter was interested or not)
• the independent variable has already or will change on its own accord (naturally)
• the researcher then measures the natural change in the dependent variable
• variables that could effect the dependent variable are not measured or controlled

Question 8

what are 3 strengths of the natural experiment?

Answer 8

1) behaviour in a natural experiment is more likely to reflect real life because of its natural setting
ie) very high ecological validaty

2) there’s less likelihood of demand characteristics affecting the results, as participants may not know they are being studied

3) can be used in situations in which it would be ethically unacceptable to manipulate the independent variable

Question 9

what are 3 limitations of the natural experiment?

Answer 9

1) they may be more expensive and time consuming than lab experiments

2) there’s no control over extraneous variables that might bias the results
-> makes it difficult for another researcher to replicate the study in
exactly the same way

3) difficult to say there is a cause and effect relationship as too many variables are unable to be controlled as so could effect the outcome

Question 10

what are quasi experiments?

Answer 10

• when the researcher doesn’t control the IV
• it’s a pre-existing difference between participants

eg) gender or age - most often in a lab