Experiments

• Experiments:

  • Researchers look to manipulate one factor to see if it will cause a change in behaviour.
  • Uses variables- factors that can be measured, manipulated + quantified.
  • Manipulate IV to see if change occurs in DV which is measured.
• Types of experiments:

  Field experiments:

  • Natural environment- less control over variables.
  • Researcher see's if manipulation of IV causes change in DV.

  Laboratory or controlled:

  • All variables but IV are controlled.
  • Casual relationship between IV manipulated + DV changing.
• Usefulness of experiments:

  • Highly scientific
  • High in reliability- can be replicated
  • Can test predictions + help prove theoretical ideas
  • Quantitative data useful for positivists.
• Practical Issues:

  • Cost of materials + lab hire
  • Gathering a sample that is representative
  • How to control variables?
  • Lack of consequences in lab experiments
• Ethical Issues:

  • Deception in lab experiments- often need to hide true aims.
  • Consent in field experiments
  • Potential for psychological harm in both forms of experiments
• Theoretical Issues:

  • Can lack variability
  • May understand behaviours but not rationale behind them as produce largely quantitative data.
  • While it is objective, researcher decides to manipulate variables, reducing research to one factor.
• Milgram's Obedience Study (1963)- Lab experiment:

  • An experiment to measure the level of obedience to authority.

  
  

  • One was learner one teacher, the participant was always the teacher and learner was a confederate of Milgram's.

  
  

  • The learner had electrodes attached to arms, teacher was in room with electric shock generator ranging from 15-450 volts.

  
  

  • Wrong answer= electric shock but teacher was unaware that learner was not actually receiving shocks.
• PET Issues of Milgram's Study:

  Practical:

  • Selected participants by newspaper advertising.
  • 636 participants
  • Time consuming

  Ethical:

  • Volts are dangerous
  • Study carries trauma
  • Unjust
  • Informed consent- did not know about shocks.

  Theoretical:

  • 18 variations- not reliable
  • Valid method
  • Only used men
• Stanford Prison Experiment- Zimbardo (1973): Controlled experiment

  • Examining impacts of deindividuation on people in institutional settings like prisons.

  
  

  • Selected sample of 24 participants from list of 75 who had tests for their physical + psychological health.

  
  

  • Half were prisoners, half were guards, prisoners taken to mock prison with uniforms + numbers.

  
  

  • Guards harassed prisoners and both sides conformed to behaviours of their role.

  
  

  • Supposed to last 2 weeks but ended after 6 days.
• PET Issues of Zimbardo's Prison Experiment:

  Practical:

  • High cost
  • Interviews = time consuming
  • Coin toss determined roles
  • 75 applied

  Ethical:

  • Emotional trauma
  • Vulnerable groups
  • Deceiving participants
  • Right to withdraw

  Theoretical:

  • Not a replica
  • Not valid- went too far.
• The Pygmalion Effect- Rosenthal + Jabobsen (1968):

  • Whether student achievement could be self-fulfilling based on teacher expectations.

  
  

  • Gave pupils IQ test and informed teachers which are average and which would be "bloomers".

  
  

  • Teachers did not expect much of the average children + gave attention to bloomers.

  
  

  • Unknown to the teachers, these students were selected randomly, after 8 months they tested pupils intelligence.

  
  

  • Bloomers IQ scores rose significantly higher than others.

  
  

  • Experiment showed teachers expectations worked as a self-fulfilling prophecy.
• PET Issues with Pygmalion Effect:

  Practical:

  • Access to participants
  • IQ test = time consuming
  • Opportunity to research

  Ethical:

  • Vulnerable group - children
  • No right to withdraw

  Theoretical:

  • Valid = NO
  • Can be repeated