EXPERIMENTS

EXPERIMENTS

1. Research method which manipulates and measures variables to discover cause and effect

2. 3 Types of experiment

   • LABORATORY - Highly controlled conditions, variable being manipulated by researcher is IV (Independent variable), change in behaviour measured by researcher is the DV (dependent variable)
     • STRENGTHS
       • Can control variables
       • Standardised procedures so easily replicable
       • Can make statements about cause and effect
     • WEAKNESSES
       • Not ecologically valid, artificial, highly controlled situation, not true to real life
       • it is not always be possible to completely control all variables. There may be confounding variables affecting the DV
       • Demand characteristics, if participant knows they are in an experiment they may change their behaviour
   • FIELD - Carried out in the natural environment, IV is still manipulated by researcher
     • STRENGTHS
       • Less demand characterisitics
       • Ecologically valid
     • WEAKNESSES
       • Harder to control variables could be many confounding varaibles
       • Ethics - Participants should give informed consent and be debriefed afterwards but difficult to do this in field experiments
   • QUASI (NATURAL) - The IV is not manipulated by the researcher, it is naturally occuring
     • STRENGTHS
       • Ecologically valid
     • WEAKNESSES
       • Harder to establish cause & effect, could be many confounding variables

3. 3 Experimental designs

   • INDEPENDENT MEASURES - different participants for each condition
   • MATCHED PAIRS - different but similar participants used for each condition, participants put in matched pairs based on key variable
   • REPEATED MEASURES - same participants used in all conditions