Research methods

• Lab experiment

  Conducted in a lab that has control over the environment
• Lab experiment evaluations

  Strengths - High reliability (findings can be checked throughout), extraneous variables are likely to be controlled

  Limitations - It can encourage demand characteristics (they know they are being watched), lacks ecological validity (hard to generalise with the environment)
• Field experiment


  Takes place in a real environment like school and the IV is manipulated to affect DV
• Field experiment evaluations

  Strengths - High ecological validity (in a real life setting), less prone to demand characteristics (less likely not to know they're being watched)

  Limitations - Lacks reliability (Little control over confounding variables), ethical issues can form (no consent for being watched)
• Natural experiment


  A real setting with a naturally occuring IV
• Natural experiment evaluations

  Strengths - Participants show no demand characterstics, very high ecological validity

  Limitations - Lacks reliability (no control over variables so difficult to replicate), Hard to establish cause-and-effect because of no control over extraneous variables.
• Quasi experiment


  Have an IV that already exists between people
• Quasi experiment evaluations

  Strengths - Often carried out in controlled conditions

  Limitations - There may be confounding variables (individual differences)
• Independent Measure Design

  Where different participants take part in each condition (one redbull and one with no redbull)
• Independent Measure Design evaluations

  Strengths - No order effects, used when repeated measure is inappopriate

  Limitations - Errors may occur due to individual differences
• Random sampling

  Anyone in the population is picked randomly

  Strengths - Fair method (no bias because everyone has an equal chance)

  Limitations - Very time consuming
• Opportunity sampling

  Being there at the moment of time (waiting at a train station)

  Strengths - Very easy and quick

  Limitation - Can result in bias and hard to generalise for the whole generation (not representative)
• Volunteer sampling

  Self selected sample where people choose to take part (with posters)

  Strengths - Participants are less likely to drop out, easy, can reach a lot of people

  Limitations - Can be bias
• Systematic sampling

  Every nth person may be taken

  Strengths - A simple method with no researcher bias

  Limitations - Very time consuming
• Stratified sampling

  Researchers divide a population into subgroups with certain characteristics

  Strengths - Representative as everyone has an equal chance of being selected
• Confounding variables

  Variables that cannot be controlled/already exist.
• Types of experimental design meaning

  The choice of how to allocate participants to experimental groups
• Matched pair design

  Forming a pair with similar participants in controlled group and the experimental group
• Why is a matched pair design a strength?

  Controls individual differences - increases internal validity
• Limitations of matched pair designs

  You can't control for every possible participant variable and matching is time consuming
• Independent groups limitations

  Participants may have a confounding variable (e.g first group may be smarter already)
• Repeated measures meaning

  The same participants repeat the same experiment again
• Order effect examples

  Participants can get better at the certain task and sometimes doing the task more than once means they can get bored.
• How to stop order effects?

  Counter-balance
• Strength of repeated measure

  Need fewer participants
• Investigator effects

  When the researcher influences the results/findings of a participant
• What can expectations cause?

  Investigator effects
• Situational variables meaning

  Anything external to the participants & researcher that could affect behaviour of the participants
• Demand characteristic meaning

  Situational variables or Investigator effects that make participants guess the aim of the study
• Ecological validity meaning

  A measure of how test performance predicts behaviors in real life settings
• Peer review


  Where other scientists analyse a study to check for flaws and ethical issues.
• Standardisation facts


  Increases validity, increases reliability, controls investigator effects and controls situational variables
• Pilot studies meaning


  small trial versions of the original study to test effectiveness and make improvements
• Falsifiability meaning


  Being able to scientifically prove that a study is false or not
• What can journals ask for?


  For changes to be made to a report based on comments from the reviewers
• Does peer reviewing involve multiple or one reviewer of the same field?

  Multiple
• What may reviewers suggest?

  For further analysis of results before anything is published
• What can a journal do?

  Decides whether to accept or reject a report based on feedback from reviewers
• Strengths of peer review?

  Can highlight any mistakes made so that researchers can improve their work. Can prevent ethical issues. Can make sure research is in high quality
• Limitations of peer review?

  Peers may not be objective in their review of report (personal bias)