Research Methods AQA A Level Psychology

• Aim


  Based on previous research. General statements that describe the purpose of the research and investigators intention
• Hypothesis


  A precise and testable prediction that clearly states the relationship between two variables and determines the nature of the research
• Independent variable


  The variable that is manipulated to test whether it has an effect
• There is a control group and experimental group(s)
• Dependent variable


  The effects of the IV on this variable are measured
• Extraneous variables


  Outside variables which could impact the research
• The main aim of all psychological research is to have as much reliability and validity as possible
• Validity


  Does the study truly measure what it is claiming to measure? If it is valid, the manipulation on the IV is causing the effect on the DV
• Internal validity


  Are research methods used appropriate to test the hypothesis
• Ecological validity


  Are findings representative of real life outside the experiment
• Population validity


  Are findings representative of other/ all people outside the sample
• Reliability


  Is there enough control in the experiment so that it could be replicated by someone else and produce similar results. Similar results are necessary to conclude that the IV causes the DV. Are there consistent high levels of control in the experiment and are extraneous variables controlled throughout the research
• Experimental group


  Ppts in the experimental group experience the manipulated IV. Their behaviour is measured / observed to see if the manipulation has an effect on the DV
• Control group


  Ppts in the control group do not experience the manipulated IV. They are used as a comparison - in the control group the behaviour should be natural and in the experimental group behaviour should be different because of the manipulation
• Operationalising


  Clearly defining variables in terms of how they can be measured, otherwise the hypothesis is not testable e.g. intelligence is too vague, you need to clarify the set of behaviours or conditions that are manipulated or measured
• Directional hypothesis


  The expected direction of the hypothesis is stated. This is the same for whether there is a positive or negative effect "higher, lower, positive, more, less"
• Non-directional hypothesis


  Predicts that there will be a difference between two conditions or groups, without stating direction of difference
• Laboratory definition


  Conducted in highly controlled environments. Not always scientific 'lab' could just be a classroom with highly controlled conditions
• Strength of lab experiments

  • High control over confounding and extraneous variables
  • Replication is easier due to high level of control
• Limitations of lab experiments

  • Lack generalisability due to fake environment - low ecological validity
  • Participants are usually aware they are being tested in a lab which contains demand characteristics
  • Results may not take place in real day life - mundane realism
• Validity of lab experiments

  Low, not a natural environment, possibility for demand characteristics
• Reliability of lab experiments

  High control of variables allows it to be repeated
• Field experiment definition


  IV is manipulated in a natural, everyday setting. Goes to participants usual environments
• Field experiment strength


  • Higher mundane realism as the environment is more natural
• Field experiment limitations


  • Loss of control over CVs and EVs, ethical issues if they are unaware they are being studied - privacy and consent
• Field experiment validity


  Higher than lab due to the more natural environment and participants may not be aware they are being studied
• Field experiment reliability


  Lower than labs due to less control over EVs and CVs therefore less repeatable
• Natural experiment definition


  The researcher has no control over the IV and cannot change it - something else causes it to change. The IV is natural but the environment may not be
• Strengths of a natural experiment

  • Provides the opportunity to study things that could not otherwise be studied due to ethical issues
  • High ecological validity due to the study of real world issues as they happen
• Limitations of a natural experiment

  • May only happen very rarely so it is harder to have opportunities to study it
  • Harder to isolate whether the IV solely impacts the DV
  • May have been conducted in a lab setting which introduces demand characteristics
• Validity of Natural Experiments

  • High - naturally occurring IV (ecological)
  • Low - may not be a natural environment (internal)
• Reliability of Natural Experiments

  These have low levels of reliability as there are hardly any controls or standardization and this makes replication very difficult
• Target population


  The large group of individuals that a particular researcher is interested in
• Sample


  Selection of the target population. This must be representative of the target population in order to generalise. Selected using sampling techniques.
• Representativeness


  Are the participants being studied a typical cross section of the target population - age gender culture ethnicity social class. If the sample is not representative of the target population then it is considered to be biased - the findings cannot be generalised to all people in the target population.
• Random sampling


  Everyone in the population has an equal chance of being studied e.g. drawing names out of a hat
• Strengths of random sampling

  • Free from researcher bias, cheap, quick, easy
• Limitations of random sampling

  • Sample is not always balanced in terms of age, gender
• Opportunity sampling


  A sample of people available to the researcher. May ask people or use anyone willing to take part. Most popular technique - often students.
• Strengths of opportunity sampling

  • Cheap, quick, easy