Lesson 4: Types of experiments

• What are the types of experimental methods mentioned?

  Lab experiments, field experiments, natural experiments, quasi experiments
• What is a key characteristic of a lab experiment?

  IV is manipulated by the researcher
• How is the DV measured in a lab experiment?

  In a controlled setting
• What are the strengths of lab experiments?

  • High internal validity
  • High reliability
• Why do lab experiments have high internal validity?

  IV is manipulated and EV is controlled
• What can be established due to high internal validity in lab experiments?

  Cause and effect relationships
• What contributes to the high reliability of lab experiments?

  Standardized procedures for all participants
• What is a limitation of lab experiments regarding ecological validity?

  They have low ecological validity
• Why do lab experiments suffer from low ecological validity?

  The setting is artificial and not real-life
• What are demand characteristics in lab experiments?

  Participants change behavior due to cues
• How do demand characteristics affect participant behavior?

  They lead to unnatural behavior
• What is a key characteristic of a field experiment?

  IV is manipulated in a natural setting
• What is a strength of field experiments regarding ecological validity?

  They have high ecological validity
• Why do field experiments have high ecological validity?

  Conducted in natural environments with everyday tasks
• What is a limitation of field experiments regarding internal validity?

  They have low internal validity
• Why is it difficult to establish cause and effect in field experiments?

  Natural settings make it hard to control EVs
• What is a limitation of field experiments regarding reliability?

  They have low reliability
• Why is it hard to replicate field experiments?

  Conditions are natural and hard to standardize
• What ethical issues may arise in field experiments?

  Deception and lack of consent
• What is a natural experiment?

  IV changes naturally without manipulation
• What is a strength of natural experiments regarding sensitive research questions?

  They allow investigation of harmful variables
• Why do natural experiments have high ecological validity?

  Conducted in natural environments with everyday tasks
• What is a limitation of natural experiments regarding internal validity?

  They have low internal validity
• Why is it difficult to establish cause and effect in natural experiments?

  IV is not manipulated and EVs are uncontrolled
• What is a quasi experiment?

  IV is based on existing differences, not manipulated
• What are the strengths of quasi experiments?

  • Conducted under controlled conditions
  • Can study sensitive research questions
• Why do quasi experiments have high reliability?

  Researchers can standardize aspects of procedures
• What is a limitation of quasi experiments regarding internal validity?

  They have low internal validity
• Why is it difficult to establish cause and effect in quasi experiments?

  Cannot randomly allocate participants to conditions
• What are the strengths and limitations of different experimental methods?

  Strengths:

  • Lab: High internal validity, high reliability
  • Field: High ecological validity, low demand characteristics
  • Natural: Ethical for sensitive questions, high ecological validity
  • Quasi: Controlled conditions, ethical for sensitive questions

  
  

  Limitations:

  • Lab: Low ecological validity, demand characteristics
  • Field: Low internal validity, low reliability, ethical issues
  • Natural: Low internal validity, low reliability
  • Quasi: Low internal validity