Research issues

• Extraneous variables are unwanted variables that may affect the change in dependant variable
• What are the two main types of extraneous variables mentioned?


  Situational variables and participant variables
• How can participant variables be defined?


  As differing individual characteristics that may impact how a participant responds in an experiment
• What are some examples of participant variables?


  Gender, age, ethnicity, socioeconomic status, intelligence, mood, clinical diagnosis
• What are situational variables?


  Aspects of the environment that might affect the participant’s behaviour
• Why should situational variables be controlled in an experiment?


  To ensure they are the same for all participants
• What are the key differences between situational variables and participant variables?


  • Situational variables: Environmental factors affecting behavior (e.g., noise, temperature)
  • Participant variables: Individual characteristics affecting responses (e.g., age, gender)
• What might be included in participant variables that impact responses in an experiment?


  Gender, age, ethnicity, socioeconomic status, intelligence, mood, clinical diagnosis
• A confounding variable

  Is an extraneous variable that interferes with the relationship between an experiment's independent and dependent variables. It's not the variable of interest but has had a direct affect on the DV, leading to inaccurate conclusions about the relationship being studied
• Demand Characteristics participants will try to work out what is going on and certain cues my help them interpret what is

  going on, how they should behave.

  • They may act in a way that they think is

  expected and over perform ( the 'please-U

  effect)

  • Deliberately underperform to sabotage the

  results (the screw-U effect).

  
  

  example, in Milgram’s research, critics argued that participants worked out that the shocks were not real and they administered them as they thought this was what was required of them.
• Investigator Effects Investigator effects are where a researcher (consciously or unconsciously) acts in a way to support their prediction. It is possible that during our energy drink study, the researcher may be include to smile more during our interactions with some participants than others. We may unknowingly in our unconscious behaviour - encourage a greater level of chattiness from the energy drink participants.
• What is the purpose of randomisation in research investigations?


  To minimise the effect of extraneous/confounding variables on the outcome
• How does randomisation increase the validity of a research study?


  By reducing the researcher’s influence on the design of the investigation
• In a study testing the effect of music on recall, what aspect should be decided randomly?


  The nature of the words used in the recall test
• Why is it important to randomise the selection of words in a recall test?


  To prevent the researcher from unintentionally influencing the results
• What could happen if the researcher decides the order of words in a recall test?


  Participants may remember more words from the easier or rhyming words at the start
• What are the key aspects of the procedure that should be decided randomly in research?


  • Nature of the words in recall tests
  • Order of presentation of stimuli
  • Assignment of participants to conditions
• STANDARDISATION • As far as is possible within an investigation, all participants should be subject to the same environment, information and experience. • This includes standardised instructions that are read to each participant. Such standardisation also means that non￾standardised changes in procedure do not act as extraneous variables. Standardisation adds control to a study thus increasing the internal validity of that study.
• Randomly allocating participants to their conditions or using a matched pairs experimental design can help to reduce participant variables. Situational variables are controlled by using standardized procedures, ensuring every participant in a given condition is treated in the same way