Scientific processes

• Methods should be empirical - based on data not theory
• Data needs to be replicable and let you establish cause and effect
• What are the 4 kinds of experiment

  • Lab
  • Field
  • Natural
  • Quasi
• What is a Lab experiment

  Control all relevant variables accept one key variable (which is altered to see what the effect is).
• What are the strengths of lab experiments

  • Control (effects of confounding variables are minimised)
  • Replication (strict controls mean you can run a study again and check the findings)
  • Causal relationships (ideally it's possible to establish whether one variable actually causes change in another)
• Weaknesses of lab experiments

  • Artificial (experiments might not measure real life behaviour)
  • Lack ecological validity
  • Demand characteristics (Participants respond according to what they think is being investigated)
  • Ethics (deception often used, making fully informed consent an issue
• What are field experiments

  Conducted outside lab settings. Behaviour measured in natural environment but a key variable is still altered so it can be measured
• Strengths of field experiment

  • Causal relationships (manipulating key variables and measuring its effect)
  • Ecological validity (less-artificial than in the lab)
  • Demand characteristics (Guess what researchers expect of them)
• Weaknesses of field experiment

  • Confounding variables (less control some stuff may happen in natural environment)
  • Ethics (Ps don't agree to take part may be distressed and not be able to debriefed)
• What is a natural experiment

  Independent variable isn't manipulated and affects dependent variable. Event occurs naturally
• Strengths of natural experiment

  • Ethics (possible to study variables that it would be unethical to manipulate)
  • Demand characteristics (participants may not know they're in a study)
  • Ecological validity (less artificial)
• Weaknesses of natural experiment

  • Causal relationships (Don't manipulate IV)
  • Confounding variables
  • Ethics (Deception often used, can't get fully informed consent)
• What is a Quasi experiment

  Researcher isn't able to R andomly A llocate to put Ps in different conditions. IV is particular feature of the participants
• Strengths of Quasi experiment

  • C ontrolled conditions
  • Ecological validity (less artificial than lab settings, more likely to generalise to real-life)