Research Methods

• What variable is measured

  DV
• what variable is changed

  IV
• what is a hypothesis


  statement that predicts the relationship between IV and DV.
• what are the 4 types of experiments


  • laboratory
  • field
  • quasi
  • natural
• Strength of laboratory experiments


  • high degree of control so replicable
• limitation of laboratory experiments


  • low ecological validity - artifical task, doesn’t look like real life
• strength of field experiments


  • high ecological validity - naturalistic so no demand characteristic
• Strength for Quasi experiment


  • replicable - controlled conditions hence high internal validity
• Limitation of Quasi experiments


  • Cofounding variables may be present as they cannot randomly allocate participants. Cause and effect may be harder to find.
• Strength of Natural experiments


  • high external validity as they are dealing with real life issues
• Limitation of Natural experiments


  • likely to not be replicable as rare situation so hard to generalise findings
• Describe independent group design


  participants only perform one condition of the IV
• Strength of independent groups design 


  • participants are less likely to guess the aim so demand characteristics are eliminated
• limitation of independent groups design


  • no control over participant variables which can alter the DV. cause and effect not as clear. Can be solved by RANDOM ALLOCATION.
• Describe repeated measures


  participants take part in all conditions of the IV.
• Strength of repeated measures


  • eliminates participants variables
  • fewer participants needed so not as time consuming
• Limitation of repeated measures


  • order effects present. Can be solved by COUNTERBALANCING
• Description of matched pairs


  participants are paired up based off of other variables then one is put in group one, the other in group 2.
• Strength of matched pairs


  • no order effects
  • demand characteristics are less of a problem
• Limitation of matched pairs


  • time consuming and expensive to match
  • large pool of participants is needed which can be hard to get
• Define directional hypothesis 


  States there is a difference in the measurement of the DV and says which way the results will go
• Difference between directional and non-directional hypothesis


  directional states which way the results will go, non-directional doesn’t
• What is null hypothesis

  no relationship between the variables
• What are the 5 sampling methods


  • random
  • Opportunity
  • Volunteer
  • Systematic
  • Statified
• Describe how to do random sampling


  1. gather all names of the sample
  2. put them in a hat
  3. take the number of participants you want out
• strength of random sampling


  no researcher bias
• limitation of random sampling


  time consuming - need a list of all members
• describe how to do opportunity sampling


  Ps that happen to be available at the time are recruited
• 2 strengths of opportunity sampling


  time saving and cheap
• 2 weaknesses of opportunity sampling


  researcher bias present

  not representative of the whole population -certain person profile may be present
• describe volunteer sampling


  Ps offer to take part in a response to an advert
• strength of volunteer sampling 


  easy and not time consuming
• weakness of volunteer sampling


  volunteer bias - may attract a certain person profile so generasibility is affected
• describe systematic sampling


  put all names in a list

  pick out an nth term e.g. 10 so every 10th person will be picked
• 2 strengths of systematic sampling

  • representative of population
  • avoids researcher bias
• describe stratified sampling


  the sample represents varying proportions of people in a particular subgroups
• 2 strengths of stratified sampling


  • no researcher bias
  • most representative
• weakness of stratified sampling 


  time consuming