Research meathords

• What 2 hypothesis are there?

  • Alternative hypothesis
  • Null hypothesis
• What is a Null hypothesis

  There will be NO difference in ....
• What 2 types of alternative hypothesis are there

  • Non - directional
  • Directional
• What is an alternative hypothesis 


  States that there will be A difference in ....
• What are the 3 types of variables

  • Independent variable
  • Dependent variable
  • Extraneous variable
• What is IV


  The variable the researcher can change or manipulate
• What is the DV


  A variable that is measured by researcher to see if IV had an affect
• What is the EV 


  A variable other than IV than can impact the results
• Types of EV

  • Order effects - this EV is shown depending on how the condition is presented (tried)
  • Ppts variables - difference between people who take part in the study (age)
  • Demand characteristics - Ppts work out the aim for the study and change their behaviour accordingly
• Experimental design - different ways Ppts can be organised for an experiment
• What are the 3 types of experimental design

  • Independent groups
  • Repeated measures
  • Matched pairs
• Independent group description 


  2 seperate groups experience 2 different conditions of the experiment
• Strengths for Independent groups

  1. No order of affects
  2. No demand characteristics
• Weakness for Independent groups

  1. Ppts aren't the same so different between group results might not be because of IV
  2. Less economical since the ppts only contributed to 1 result
• Repeated measures description 


  1 group of Ppts experience all conditions of the experiment
• Strengths of Repeated measures

  1. No issue with Ppts variables
  2. More economical
• Weakness to Repeated measures

  1. Are order of effects
  2. There can be demand characteristics
• Matched pairs description 


  2 separate groups of ppts experience 2 types of experiments but they are matched based on certain characteristics before experiment takes place
• Strengths of Matched pairs

  1. No order of effects
  2. Ppts variables are reduced
• Weakness of Matched pairs

  1. Although there is an attempted Ppts can never match exactly
  2. Matching ppts also take lots of time
  3. Less economical
• Sampling meathords - a way for a researcher to narrow down the target population to use in research
• What are the types of sampling methods

  • Random
  • Opportunity
  • Systematic
  • Stratified
• What is random sampling 


  Every member has an equal chance of being selected
• Strengths of Random sampling 


  Should be representative since everyone has equal chance
• Weakness of Random sampling 


  Takes time and effort
• What is opportunity sampling 


  Sample is produced by people who are available and willing to to take part at that time
• Strengths of Opporitunity sampling 


  Every member has an equal chance to be selected
• Weakness of opportunity sampling 


  Unrepresentative if drawn from one place and difficult to generalised
• What is Systematic sampling 


  Every nth member of the target population is selected for the sample
• Strengths for Systematic sampling

  Avoids researcher bias and likely to be representative
• Weakness of Systematic sampling 


  Althought usually representative it can be baised since all ppts can be men
• What is Stratisfied sampling 


  Sample produced by selecting ppts in proportion to their frequency in target population ( Sample of 20 = 10 male and 10 female)
• Strengths of Stratisfied sampling 


  Most representative
• Weakness of Stratisfied sampling 


  Time consuming and those selected might not want to participate
• What are the 3 types of experiments

  • Lab
  • Field
  • Natural
• What is a Lab experiment 


  It takes place in a controlled environment where researcher can chose an IV to measure the effect it has on the DV
• Strengths for the Lab 


  EV can be easily controlled
• Weaknesses to the Lab 


  Not like every day life therefore it lacks ecological validity and there is an increace chance of demand characteristics
• What is a Field experiment 


  It takes place in a natural setting but the researcher still creats an IV to measure effect on DV
• Strengths to the Field 


  More realistic and higher ecological validity