Keywords

• Aims


  the general purpose of an investigation
• Operationalising variables


  clearly defining variables so they can be measured
• Hypothesis


  precise statement about the expected outcome of the study
• Directional hypothesis - 1 tailed

  • states the direction or difference between the two levels of study
  • e.g. average recall will be significantly higher for the immediate recall rather than delayed
  • a one tailed hypothesis is used when there is past research that indicates it would go in a particular direction
• Non directional hypothesis- 2 tailed

  • not sure of the direction of the data
  • "there will be a significant difference in the scores on a psychology test"
  • used if there is no previous research that indicates direction
• Null hypothesis

  • suggesting that there is no diff in the data
  • "no significant difference between ..."
• Confounding variable


  type of extraneous variable
• Extraneous variables


  variables other than the IV that may have an effect on the DV if not controlled

  • participant - characteristics of Ps that may affect out come
  • situational - environmental factors
  • investigator effects - unconscious bias
  • demand characteristics- cues that Ps pick up on - "please you" or "screw you" effect
• Minimising extraneous variables 


  • random allocation - minimise P variables to conditions in an independent design
  • matched pairs design can also help this
• Minimising extraneous variables 


  • standardisation - used to keep the research environment the same for all Ps
  • used as a way of controlling for situational variables
  • standardised instructions
• Minimising extraneous variables 


  • standardised instructions can ensure that any unconscious bias can be prevented
  • double blind procedures can be used to prevent bias
• Demand characteristics


  single blind is where the participant is unaware of the aims of the study and engages in it