experiments

• types of experiments:

  lab

  quasi

  natural

  field
• lab experiments:

  -controlled environment

  -measured DV

  -manipulated IV

  -standardised
• lab experiments

  strengths:

  control

  reliability

  weakness:

  ecological validity
• field experiments:

  natural environment

  manipulated IV

  measured DV

  some EV’s controlled
• field experiment

  strengths:

  ecological validity

  reduced demand characteristics

  weakness:

  control
• quasi experiment

  controlled environment

  pre-existing IV

  measured DV

  standardised
• quasi experiment

  strength:

  high reliability

  weakness:

  confounding variables
• natural experiment:

  natural environment

  no control

  IV manipulated

  DV measured
• natural experiment

  strengths:

  ecological validity

  reduced demand characteristics

  weakness:

  control
• the experimental designs are:

  independent groups

  repeated measures

  matched pairs
• independent groups:

  different people in each condition

  strengths:

  no order effects

  reduced demand characteristics

  weakness:

  individual differences
• repeated measures: same people in both conditions

  strength:

  less individual differences

  weaknesses:

  more demand characteristics

  order effects

  HOWEVER

  order effects can be eliminated with counterbalancing (ABBA)
• matched pairs:

  pre test

  match participants with similar scores

  randomly allocate to conditions

  compare the pairs’ results
• matched pairs

  strengths:

  less individual differences

  reduced order effects and demand characteristics

  weakness:

  individual differences