Variables

• IV?


  Variable that is manipulated/changed
• DV?


  Variable that alters as a consequence of the IV/measured
• Extraneous variables?


  Variables that influence the outcome of the experiment but aren't the variables under investigation
• What is a con-founding variable?


  A variable that effects only one condition not both - it effects it more than the other one or completely differently
• What is a random variable?

  It is likely to affect both groups equally
• Why is operationalising variables important?


  its important for the research to be taken seriously
• Operationalising variables

  way vairables are defined and measured has important implications for the statistical test that will be used to analyse the resulting data

  if you don’t operationalising variables effectively the research will not be valid
• Operationlisation?

  Giving precise definitions and descriptions of what will be measured
• When is a variable been operationalised?

  when it has been turned into something that can be measured
• Defining variables?


  stating what the DV and IV are
• What affects the DV?

  Extraneous and confounding variables

  It can invalidate the results and be a serious problem
• Extraneous variables are beyond the control of the researcher and they will affect the ps in a random fashion

  hoped that the errors that result from the variables will not systematically affect one condition or the experiment more that another
• What might result from extraneous variables?


  some loss of sensitivity
• How do confounding variables affect the DV?

  Reduces internal validity - no longer sure that the IV is responsible for the results seen
• Confounding variables may not affect all the conditions of an experiment equally

  Constant errors are very serious and can lead to false conclusions
• How to deal with confounding variables?

  try to spot the before you start the experiment and either eliminate them completely or make sure they’re held ata a constant through all the conditions

  Counterbalancing, randomisation and standardisation are the ways to make sure the investigation isn’t confounded