Experimental methods/ types of experiments

• A laboratory experiment is an experiment conducted under highly controlled conditions where ‘accurate’ measurements are possible. All extraneous variables can be controlled so that any changes in the DV can be said to be due to changes in the IV. The researcher decides where and when and with which participants (standardized procedure).
• Standardized procedure: procedures that are kept the same • Ecological validity: ability to generalise to the population • Internal validity: the degree of confidence that the relationships being tested is trustworthy and not influenced by other variables
• What is a strength of lab experiments regarding control over variables?


  Lab experiments have high control over CV's and EV's.
• Why is high control over variables in lab experiments beneficial?


  It ensures that any effect on the dependent variables is likely due to manipulation of the independent variables.
• What does high internal validity in lab experiments indicate?


  It indicates that the study accurately measures what it intends to measure.
• How does a standardized procedure benefit lab experiments?


  It makes it easier to replicate the study.
• What is a weakness of lab experiments related to participant behavior?


  Artificial environments may cause social desirability.
• What are demand characteristics in the context of lab experiments?


  They are cues that influence participants to behave in a way they think the researcher wants.
• What is the risk associated with the investigator effect in lab experiments?


  The investigator effect can bias the results based on the researcher's behavior or expectations.
• Why do lab experiments often have low external/ecological validity?


  They usually use a small sample size.
• What does low mundane realism mean in lab experiments?


  It means that tasks may not represent everyday experiences.
• What are the strengths and weaknesses of lab experiments?

  Strengths:

  • High control over CV's and EV's
  • High internal validity
  • Easier to replicate due to standardized procedures

  
  

  Weaknesses:

  • Artificial environments may cause social desirability
  • Risk of demand characteristics and investigator effect
  • Usually small sample size leading to low external/ecological validity
  • Low mundane realism
• Standardized procedure: procedures that are kept the same • Ecological validity: ability to generalise to the population • Internal validity: the degree of confidence that the relationships being tested is trustworthy and not influenced by other variables • Mundane realism: the degree to which the materials/procedure involved in an experiment are similar to events in the real world.
• Field experiments:

  Still involve the manipulation of an IV to measure its effects on the DV, but in a real-life setting (so cannot really control extraneous variables). Take place in a more natural setting such as schools, hospitals etc, (where behaviour would normally occur)
• What is a strength of field experiments regarding ecological validity?


  They reflect real life better due to their natural setting.
• Why are demand characteristics less likely to affect field experiments?


  Participants may not know they are being studied.
• What ethical issue is associated with field experiments?


  Participants often cannot give informed consent.
• What is a strength of field experiments regarding ecological validity?


  Field experiments have higher ecological validity than lab experiments.
• What is a limitation of field experiments regarding extraneous variables?


  There is less control over extraneous variables that might bias results.
• Why might behavior in a field experiment reflect real life more accurately?


  Because of its natural setting.
• Why are field experiments difficult to replicate?


  They are difficult for another researcher to replicate in exactly the same way.
• What reduces the likelihood of demand characteristics in field experiments?


  Participants may not know they are being studied.
• How does less control in field experiments affect internal validity?


  Less control can produce low internal validity.
• What is a major ethical issue associated with field experiments?


  Participants are often unaware they are taking part, so they cannot give informed consent.
• What is a consequence of having less control over extraneous variables in field experiments?


  It might bias the results.
• What is internal validity?


  Internal validity is the degree of confidence that the relationships being tested are trustworthy and not influenced by other variables.
• What is ecological validity?


  Ecological validity is the extent to which results can be generalized to the real world.
• Why are field experiments difficult for other researchers to replicate?


  Because they are difficult to replicate in exactly the same way.
• What can less control in field experiments lead to regarding internal validity?


  It can produce low internal validity.
• What is internal validity?


  • The degree of confidence that the relationships being tested are trustworthy
  • Not influenced by other variables
• What is ecological validity?


  • The extent to which results can be generalized to the real world
• What is a natural experiment?


  A natural experiment is when the researcher has no control over the independent variable (IV).
• Why can't the researcher change the independent variable in a natural experiment?


  Because someone or something else causes the IV to vary.
• Give an example of a situation that could be studied using a natural experiment.


  Before and after a natural disaster.
• What does it mean when it is stated that "it is the IV that is natural, not necessarily the setting"?


  It means that the independent variable varies naturally, regardless of the experimental environment.
• When are natural experiments often conducted?


  When it is not ethical or practical to manipulate the independent variable.
• What was the focus of Williams' (1986) study in a Canadian town?


  • Monitored changes in behavior of 6-11 year old children
  • Observed before and after television was introduced
• What significant change was recorded in Williams' (1986) study after children had access to TV?


  Significant increases in aggression were recorded.
• What is one strength of natural experiments?


  They provide opportunities for research that may not otherwise be undertaken.
• How does the introduction of television relate to the concept of a natural experiment in Williams' study?


  The introduction of television serves as a naturally occurring independent variable affecting children's behavior.