Research Methods

• Explain a laboratory experiment

  Carried out in a controlled experiment, variables can be carefully manipulated and pps are aware they're taking part in the study
• Advantages of a lab experiment

  It can be easily replicated due to high levels of control and high internal validity
• Disadvantages of lab experiment

  Low ecological validity due to artificial settings and demand characteristics (pps become aware of aims of study so act differently)
• Explain a field experiment

  Conducted in a more normal environment, IV is still manipulated and DV is measured by researcher and pps aren't aware they are taking part
• Advantage of field experiments

  High ecological validity so results can be generalised beyond research setting and lack of demand characteristics due to real life setting
• Disadvantages of field experiments

  Low internal validity as less control over CV + EV and less easy to replicate due to low control over variables
• Explain a natural experiment

  Conduced when it is not possible for ethical or practical reasons to manipulate the IV (it occurs naturally)
• Advantages of natural experiment

  Allows research where IV can't be manipulated and high ecological validity
• Disadvantages of natural experiments

  Lack of casual relationship as IV isn't directly manipulated and lack of random allocation so results may be affected by CV
• Explain a quasi - experiment

  Can be done to a lab, field and natural, the iv is simply a difference between people that exists (gender + age) and the DV is still measured
• Advantages of a quasi - experiment

  Allows comparisons between types of people and can be carried out in a lab so high control and easy replication
• Disadvantages of a quasi - experiment

  Lack of random allocation and if done in a lab may cause low ecological validity
• What is a independent variable?

  Variable that is controlled/manipulated
• What is a dependent variable?

  The variable that is measured in the experiment
• What is a confounding variable?

  Variables that aren't controlled by the experimenter and can affect the results (e.g. mood, personalities and individual differences)
• What is a extraneous variable?

  Anything other then the IV which might effect the DV and can be controlled by the experimenter (e.g. age and time limits)
• What is an aim?

  Stated intention of what the experimenter plans to discover
• What is a hypothesis?

  Formal, unambiguous statement of what is predicted to happen. Must contain conditions of IV, outcome of DV, be operationalised and measured
• What's a null hypothesis?

  A statement of no difference between the groups/conditions being studied
• What's a directional hypothesis?

  States the direction of the DV whether it's expected to be greater/ less, positive/negative between the two groups/conditions
• What's a non directional hypothesis?

  Doesn't state the direction of the DV just that there will be a difference between the groups/conditions studied
• What's internal reliability?

  Each person in a study is treated the same way
• What's external reliability?

  Same results found after a repeated test
• How do you assess reliability?

  Test retest reliability - same sample, same test but with a time gap

  Inter observer reliability - when using 2+ observers so you can compare results
• How do you improve reliability?

  Repetition
• What's internal validity?

  Measure what it is meant to measure
• What's external validity?

  Can it be generalsied beyond experimental setting
• What's ecological validity (external) ?

  Is the setting realistic enough to generalise to the public
• What's population validity (external)?

  Is the sample applicable enough to generalise
• What's temporal validity (external) ?

  It is relevant to society now
• How do you assess validity?

  Face validity - whether it looks like it measures what it should

  Concurrent validity - Whether findings are similar to those in a well established test
• How do you improve validity?

  Larger sample size and more realistic setting
• Explain an independent groups design

  • Recruit a group and divide them into two randomly
  • First group does the task with the IV set for condition one
  • Second group does the task with the IV set for condition two
  • Measure the DV for each group and compare
• Advantages of independent groups

  Quick and no demand characteristics
• Disadvantages of independent groups

  Need two investigators which could led to the investigator effect and participant variables
• Explain a repeated measures design

  • Recruit a group of pps
  • First, the group does the IV set for condition one
  • Secondly, the group does the IV set for condition two
  • Measure the DV for each condition then compare
• Advantages of repeated measures

  No pps variables and no investigator effect
• Disadvantages of repeated measures

  Demand characteristics and takes long to do as pps will need a break between each condition
• Explain a matched pairs design

  • Find out about the people in your group
  • Order them in a factor that relates to your experiment then pair them up
  • One person in the pair will do condition one and the other will do condition two (like independent measures)
  • Collect results then compare
• Advantages of matched pairs

  fewer pps variables and no demand charactertistics