Research Issues

• What is an extraneous variable?

  Any variable other than the independent variable
• Why should extraneous variables be identified at the start of a study?

  To minimize their influence on results
• What are the two types of extraneous variables?

  • Participant Variables: Individual differences affecting results
  • Situational Variables: Features of the experimental situation affecting results
• What is a confounding variable?

  Extraneous variables that change with the independent variable
• Why is it difficult to determine the cause of changes in the dependent variable?

  Confounding variables may influence the results
• What are demand characteristics?

  Cues indicating the study aims to participants
• How can demand characteristics affect participant behavior?

  Participants may change their behavior in response
• What are the two effects related to demand characteristics?

  • Please-U Effect: Participants act to please the experimenter
  • Screw-U Effect: Participants underperform to sabotage results
• What are investigator effects?

  Researcher actions that support their predictions
• How can a researcher unintentionally influence a study?

  By communicating feelings about observations
• What are the two methods to deal with investigator effects?

  • Single-Blind Method: Participant is unaware of study aims
  • Double-Blind Method: Both participant and experimenter are unaware
• What is randomization in research?

  Using chance methods to reduce biases
• What is the purpose of standardization in research?

  To ensure uniform procedures for all participants
• What is the result of non-standardized changes in procedures?

  They act as extraneous variables