Research issues

• Extraneous Variables

  • Additional unwanted variables
  • These should be identified prior to research and minimised
• confounding variable

  • when an extraneous variable has impacted on the results of a study
• demand characteristics

  • cues from a researcher or the research situation that may be interpreted by participants as revealing the purpose of the study
  • participant may change their behaviour in the experiment
  • please u effect - act in a way they think the experimenter wants them to act
  • screw u effect - they may underperform deliberately in an attempt to Sabotage the results
  • demand characteristic = type of extraneous variable
• randomisation

  • use of chance methods ( raffle method ) to control for the effects of bis when designing materials
  • example if doing memory test - randomise the words .
• standardisation

  • way of controlling extraneous variables
  • all participants - same environment , info and experience
  • e.g. standardised procedures and instructions.
  • allows researchers to. concludes any changed to dv were due to the IV
• extraneous variables four types

  • demand characteristic
  • participant variables
  • situational variables
  • investigator effects
• participant variables

  • any individual differences - characteristics - between participants that may effect the dependent variable
  • example : age , motivation , gender
• situational variables

  • any features of the experiment situation that may affect the DV
  • example : weather , noise , time of day .
• investigator effects.

  • the behaviour of characteristics of the researcher such as their tone of voice , mannerism , which might unintentionally influence participants.