Control of Variables

• What is the main purpose of controlling variables in an experiment?

  To ensure that only the independent variable affects the dependent variable
• What is an extraneous variable?

  An extraneous variable is any variable that affects the dependent variable but is not the independent variable
• How do extraneous variables differ from confounding variables?

  Confounding variables change systematically with the independent variable, while extraneous variables do not
• Why is it important to control confounding variables in an experiment?

  To ensure that the researcher can determine the true cause of changes in the dependent variable
• What is an example of a confounding variable in a sleep study?

  The time of day the experimental task is completed
• What are demand characteristics in research?

  Demand characteristics are cues that make participants guess the aim of the investigation
• What is participant reactivity?

  Participant reactivity is when participants change their behavior due to cues from the research situation
• What is the 'Please-U effect'?

  The 'Please-U effect' is when participants act in a way they think the researcher wants
• What is the 'screw-U effect'?

  The 'screw-U effect' is when participants intentionally underperform to sabotage the study's results
• How do demand characteristics affect the validity of research results?

  They can lead to unnatural behavior, affecting the validity of the results
• What are investigator effects?

  Investigator effects are unwanted influences from the researcher's behavior on the dependent variable
• What factors can contribute to investigator effects?

  Factors include study design, participant selection, and researcher interaction
• What is randomisation in research?

  Randomisation is the use of chance to reduce bias from investigator effects
• What is standardisation in research?

  Standardisation involves using the same procedures and instructions for all participants
• What are the steps to minimize the effects of extraneous or confounding variables?

  • Use randomisation to reduce bias
  • Implement standardisation for procedures and instructions