psychology research methods

• Experimental method


  Manipulation of an independent variable (IV) to have an effect on the dependent variable (DV), which is measured and stated in results
• Types of experiments


  • Field
  • Laboratory
  • Quasi
  • Natural
• Aim


  A general statement made by the researcher which tells us what they plan on investigating, the purpose of their study
• Hypothesis


  A precise statement which clearly states the relationship between the variables being investigated
• Types of hypotheses


  • Non-directional
  • Directional
• Independent variable (IV)


  The aspect of the experiment which has been manipulated by the researcher or simply changes naturally to have an effect on the DV
• Dependent variable (DV)

  The aspect of the study which is measured by the researcher and has been caused by a change to the IV
• Operationalisation


  The act of a researcher clearly defining the variables in terms of how they are being measured
• Extraneous variable


  Any other variable which is not the IV that affects the DV and does not vary systematically with the IV
• Confounding variable


  A variable other than the IV which has an effect on the DV and changes systematically with the IV
• Demand characteristics


  Any cue the researcher or the research situation may give which makes the participant feel like they can guess the aim of the investigation
• Participant reactivity


  Participants changing their behaviour to fit the situation rather than acting naturally
• Investigator effects


  Any unwanted influence from the researcher's behaviour, either conscious or unconscious, on the DV measured
• Randomisation


  The use of chance to reduce the effects of bias from investigator effects
• Standardisation


  Using the exact same formalised procedures and instructions for every single participant involved in the research process
• Population


  The group of people from whom the sample is drawn
• Sampling methods


  • Opportunity sampling
  • Random sampling
  • Systematic sampling
  • Stratified sampling
  • Volunteer sampling
• Experimental designs


  • Independent groups design
  • Repeated measures
  • Matched pairs
• Single-blind procedure


  A research method in which the researchers do not tell the participants if they are being given a test treatment or a control treatment
• Double-blind


  A research method in which neither the participants nor the researchers know which participants are receiving the test treatment and which are receiving the control treatment
• A pilot study is a small-scale version of an investigation which is done before the real investigation is undertaken
• Pilot studies are carried out to allow potential problems of the study to be identified and the procedure to be modified to deal with these
• Pilot studies also allow money and time to be saved in the long run
• Double blind studies are particularly useful for preventing bias due to demand characteristics or the placebo effect
• Double blind studies give a way to reduce the investigator effects as the investigator is unable to unconsciously give participants clues as to which condition they are in
• Control group/condition


  Sets a baseline whereby results from the experimental condition can be compared to results from this one
• If there is a significantly greater change in the experimental group compared to the control then the researcher is able to conclude that the cause of effect was the IV
• Naturalistic observation


  Watching and recording behaviour in the setting where it would normally take place
• Naturalistic observation


  • High ecological validity
  • High external validity as done in a natural environment
• Naturalistic observation


  • Low ecological validity if participants become aware that the are being watched
  • Replication can be difficult
  • Uncontrolled confounding and extraneous variables are presented
• Controlled observation


  Watching and recording behaviour in a structured environment e.g. lab setting
• Controlled observation


  • Researcher is able to focus on a particular aspect of behaviour
  • There is more control over extraneous and confounding variables
  • Easy replication
• Controlled observation


  • More likely to be observing unnatural behaviour as takes place in an unnatural environment
  • Low mundane realism so low ecological validity
  • Demand characteristics presented
• Overt observation


  Participants are watched and their behaviour is recorded with them knowing they are being watched
• Overt observation


  • Ethically acceptable as informed consent is given
  • More likely to be recording unnatural behaviour as participants know they are being watched
  • Demand characteristics likely which reduces validity of findings
• Covert observation


  The participants are unaware that their behaviour is being watched and recorded
• Covert observation


  • Natural behaviour recorded hence high internal validity of results
  • Removes problem of participant reactivity
  • Ethical issues presented as no informed consent given
• Participant observation


  The researcher who is observing is part of the group that is being observed
• Participant observation


  • Can be more insightful which increases the validity of the findings
  • There's always the possibility that behaviour may change if the participants were to find out they are being watched
  • Researcher may lose objectivity as may start to identify too strongly with the participants
• Non-participant observation


  The researcher observes from a distance so is not part of the group being observed