Experimental methods

• What is a matched pairs design?

  When participants are matched on a specific characteristic
• Types of experimental designs

  independant groups

  Repeated measures

  Matched pairs
• Advantage of using independant groups

  two conditions can be completed at once

  pps are not effected by order effects
• How to control the effect of extraneous variables

  random allocation

  testing all participants in the same room

  making sure that all participants hear the same instructions

  ensuring that all participants are tested by the same researcher.
• What are the measures of dispersion

  range

  standard deviation
• How is random allocation used?

  • pps allocated to a number
  • numbers put in a hat
  • assign first three number drawn to a group and repeat
• What is a operationalised dependent variables?

  an operationalised DV will create quantitative data
• How to calculate s value

  minus all number that didnt make a difference- then pick the category with smallest number
• What is statistical tests used for?

  researchers use statistical tests to determine the likelihood that the effect/difference/relationship they have found has occurred due to chance.
• What is the dependant variable?

  something you measure
• Advantage of using a stratified sampling?

  ensures that this sample is truly representative because different types of people (males / females) working in this company are represented in the sample in the correct proportions
• strength of using random sample

  more likely to be representative of the target population; able to generalise to the target population; to exclude researcher bias
• limitation of using independant groups

  individual differences
• what is extraneous variables?

  A variable other than the independent variable or an additional / or another variable that might have an effect on the dependent variable
• why is a pilot study completed?

  A pilot study is used to check aspects of the research such as whether participants understand standardised instructions, whether timings are adequate etc. It allows the researcher to try out the study with a few participants so that adjustments can be made before the main study, so saving time and money