types of experiments

• Distinguish between the types of experiments.

  Experimenter manipulated the independent variable

  Laboratory experiment The experimenter manipulates the IV in a controlled environment where the behaviour being investigated may not usually occur.

  Field experiment The experimenter manipulates the IV in a natural setting where the behaviour being investigated would usually occur.
• Distinguish between the types of experiments. Experimenter did not manipulate the independent variable

  Natural experiment The IV is a naturally occurring event that has happened

  without the experimenter manipulating it (e.g. losing a job).

  Quasi experiment The IV is a pre-existing differenc between participants that the experimenter has not manipulated (e.g. their age, sex etc.)
• Why is it difficult to employ standardised procedures in field experiments?

  🔴 Field experiments occur in real-world settings where situational variables are hard to control, making replication difficult and reducing reliability.
• Why is it easy to employ standardised procedures in laboratory experiments?

  🟢 Lab experiments take place in controlled environments where situational variables can be managed, making replication easier and increasing reliability.
• Why do laboratory experiments lack ecological validity?

  🔴 They are conducted in artificial settings where behaviour does not naturally occur, meaning findings may not reflect real-world behaviour, reducing validity.
• Why do field experiments have high ecological validity?

  🟢 They take place in natural settings where behaviour would typically occur, making findings more reflective of real-life situations and increasing validity.
• Why is there a reduced risk of demand characteristics in field experiments?

  🟢 Participants may be unaware they are part of a study, meaning they are less likely to guess the aims and change their behaviour, increasing validity.
• Why is there a high risk of demand characteristics in laboratory experiments?

  🔴 Participants know they are being studied in an artificial setting, making them more likely to guess the aims and alter their behaviour, reducing validity.
• Why can field experiments be considered unethical?

  🔴 Participants may not know they are part of a study, meaning they might not be able to give informed consent or withdraw, questioning the study's ethical appropriateness.
• Why can laboratory experiments be considered ethical?

  🟢 Participants are aware they are part of a study, allowing them to give informed consent and withdraw if they choose, increasing ethical appropriateness.