experimental method

• What does the experimental method involve?

  Manipulation of an independent variable
• What is the aim of a study?

  A general statement of the investigation purpose
• What is a hypothesis?

  A testable statement about variables
• What is a directional hypothesis?

  States the direction of the difference
• Give an example of a directional hypothesis.

  People who drink coffee are more talkative
• What is a non-directional hypothesis?

  States there is a difference without direction
• Give an example of a non-directional hypothesis.

  People that drink coffee differ in talkativeness
• What are variables in an investigation?

  Things that can vary or change
• What is an independent variable (IV)?


  Manipulated aspect of the experimental situation
• What is a dependent variable (DV)?

  The variable measured by the researcher
• What does operationalisation mean?

  Defining variables in measurable terms
• Provide an example of operationalisation.

  Participants say more words after drinking coffee
• What is the key to any experiment?

  Manipulating the IV to affect the DV
• What are extraneous variables?

  Variables that may interfere with the IV
• What is experimental design?

  Ways participants are organized in experiments
• What are the types of experimental designs?

  • Independent groups design
  • Repeated measures design
  • Matched pairs design
• What is independent groups design?

  Participants are allocated to different groups
• What is repeated measures design?

  All participants take part in all conditions
• What is matched pairs design?

  Participants are paired on relevant variables
• What is random allocation?

  Ensures equal chance of condition assignment
• What is counterbalancing?

  Controls order effects in repeated measures
• What is the purpose of independent groups design?

  To compare performance of two separate groups
• What is the issue with independent groups design?

  Participant variables may confound results
• What is a strength of independent groups design?

  Order effects are not a problem
• What is a disadvantage of repeated measures design?

  Order of tasks may affect results
• What are order effects?

  Effects due to the sequence of tasks
• What is a strength of repeated measures design?

  Controls participant variables effectively
• What is a disadvantage of matched pairs design?

  Participants can never be matched exactly