experiments/observations

• Laboratory experiments are conducted in highly controlled environments. The researcher manipulates the IV and records the effects of the DV. The pps in a lab experiment can be randomly allocated to conditions. A lab experiment is therefore considered a true experiment.
• Lab experiments

  Strengths: 

  High control over extraneous variables meaning cause and effect can be established.  

  Replication is possible due to high level of control. This also means results can be checked for reliability. 
• Lab experiments

  Weaknesses;    

  Pps are often aware of being tested- possible demand characteristics.

  Artificial experiment means it may lack generalisability.

  Investigator effects may occur (unless it is a double blind experiment- this is when both the pps and the researcher conducting the experiment does not know the aims of the investigation)
• In field experiments the researcher still manipulates the IV and records the effects on the DV but the experiment is conducted in a real life setting. 
• Field experiments

  Strengths: 

  High ecological validity due to being conducted in a real life setting. 

  Behaviour is likely to be more valid and authentic (less demand characteristics)
• Field experiments

  Weaknesses:

  There is less control over extraneous variables (these will be different depending on the experiment)

  It’s difficult to replicate them completely because they tend to be less controlled. 

  Possible ethical issues if pps are unaware they’re being studied. 
• A natural experiment is where the researcher takes advantage of a naturally occurring IV and the effect it has on the DV. The researcher has not manipulated the IV directly, the IV would vary naturally whether or not the researcher was interested. 

  The researcher cannot randomly allocate pps to conditions and/or has no control over the IV. This is not a ‘true’ experiment. 
• Natural experiment

  Strengths:

  Provides opportunities for research that may not be otherwise conducted due to practical/ ethical reasons.

  They have high external validity because they involve the study of real-life.
• Natural experiment

  Weaknesses:

  A naturally occurring event may happen, rarely limiting generalisation to other situations.

  Pps may not be randomly allocated to conditions. 
• Quasi-experiments:

  Studies that are almost experiments. The IV is not something that varies at all- it is simply a difference between people that exist. The researcher records the effects of this ‘quasi-IV’ on the DV. The researcher cannot randomly allocate pps to conditions and/or has no control over the IV. This is also not a ‘true’ experiment. 
• Quasi experiment

  Strengths:

  Carried out under controlled conditions and share the strengths of a lab experiment.
• Quasi experiment

  Weaknesses: 

  Pps are aware of being tested- possible demand characteristics.

  Pps cannot be randomly allocated and therefore there may be confounding variables. 
• Naturalistic observation

  Takes place in the pps natural environment. The researcher does not interfere in any way with what’s happening. 
• Naturalistic observation

  Strengths: 

  provide a realistic picture of behaviour and therefore have external validity, although this may be less so if pps are aware of being observed. 
• Naturalistic observation

  Weaknesses:

  due to lack of control there may be uncontrolled extraneous variables that may actually influence the behaviour observed. 

  Naturalistic observations tend to be one of situations and makes replication challenging. 
• Controlled observations:

  Takes place in a controlled environment provided by the researcher. The researcher can control some of the variables, but it does reduce the ‘naturalness’ of the environment/ behaviour being studied. 
• Controlled observations:

  Strengths:

   Controlled observations mean the researcher can focus on particular aspects of behaviour and also being controlled means extraneous variables are less of a problem and replication becomes easier. 
• Controlled observations

  Weaknesses:

  Making an environment more controlled can sometimes impact on how the pps behave. This may be less natural because of the environment. 
• overt observation


  pps are aware they are being observed
• overt observation strength 


  ethical advantages as pps are aware of whats going on and have given consent.
• overt observation weakness

  having the awareness could mean pps behave differently to normal and behaviour is not natural, lacking internal validity.
• covert observation


  pps are unaware they are the focus of a study,
• covert observation strength

  good internal validity; pps are unaware they are being observed, behaviour will be natural (less likely to suffer from demand characteristics)
• covert observation weakness

  ethics of these studies may be questioned, as pps may not wish for their behaviour to be studied without their initial consent
• pps observation

  observer becomes part of the group they are studying
• pps observation strength

  provide real insight into the pps being studied and this richness may not be gained in any other way; increases internal validity
• pps observation weakness

  danger the observer may identify too strongly with those they are studying and as a result lose their objectivity.
• non-pps observation


  observer is merely watching/ listening to the behaviour of others and remains separate from the pps in the study
• non-pps observation strength

  more likely to remain objective because they are not apart of the group being studied.
• non-pps observation weakness

  may lose valuable insight into the pps as they are too removed from the pps and behaviour, decreasing internal validity