Cards (16)

  • what is an independent variable?
    something that a researcher changed or manipulates
    • in order to test the affect of IV we need different experimental conditions and we need a comparison
  • what is the dependent variable?
    the variable that is measured by the researcher.
    • any effect on the DV should be caused by the IV
    • a well written hypothesis should make it easy to tell what the IV and DV are
  • operationalization of variables :
    we have to operationalise variables to make it testable so it needs to be very measurable, therefore very clear
    e.g use numbers (300ml) and names (lucozade)
  • extraneous variables:
    any variables ,other than the IV, should be be controlled or removed as it can affect the dependent variable
    • unwanted, extra variables
    • are identified before the study by the researcher, who takes steps to minimise their influence
    • most are straightforward to control e.g age and lighting, but some so not vary systematically with the IV
  • what are the two types of extraneous variables?
    participant variables
    situational variables
  • what are participant variables?
    any individual differences between participants that could affect the DV
  • what are situational variables?
    any features of the experimental situation that may affect the DV
  • what variables are these examples of:
    • age
    • personality
    • motivation
    • intelligence
    participant
  • what variables are these examples of:
    • noise
    • time of day
    • temperature
    • weather
    situational
  • confounding variables:
    • they change systematically with the IV
    • we cannot tell if there are any changes in the DV and if it’s due to the IV or confounding variables - can become an unintentional IV
    • variables you find after the study that can influence the DV
  • application to marshmallow test: participant variables
    • if the child is used to waiting for things normally
    • if they have a sweet tooth
    • if they were hungry or had eaten something previously
  • application to the marshmallow test: situational variables
    • ensure they are tested in the same room
  • demand characteristics:
    • participants are not passive within an experiment and are likely to spend a lot of the time trying to make sense of the situation
    • this is a significant extraneous variable in experimental research and is very difficult to control
    • cues may help ppts figure the aims of the study
    • as a result, they may act in a way they think is expected and over-preform (please U effect) or they may act in a way to sabotage the study (screw U effect)
    • therefore the behaviour is unnatural
  • investigator effects:
    things that you do that could influence the participants of the behaviour
    • for example, if the researcher is smiling more at a certain participant, it may encourage behaviour, and cause the please U effect
    • it refers to the unwanted influence of the investigator on the research outcome
  • randomization:
    in an investigation a researcher can take simple steps to minimize the effect of extraneous/confounding variables on the outcome
    • randomization= use of chance methods to reduce the researchers unconscious bias when designing an investigation (attempt to control investigator effects)
  • standardization:
    • all participants should be subject to the same environment, information and experience
    • to ensure this , all procedures are standardized, so a list of ectactly what should be done in the study
    • e.g standard instructions to read to each ppt, so that there are no extraneous variables