Pyschology: Research methods

• Experimental method: involves manipulation of IV to have an effect on the DV which is measured.
• Operationalised- clearly defined in how they are being measured. Turning a variable into something measured. e.g kg, cm

  Inaccurate operationalisation leads to unreliable results and cannot be replicated
• Extraneous variables: variables that is not the IV which could affect the DV and SHOULD be controlled. Uncontrolled extraneous varibles would lead to confounding variables. Can unintentionally affect results
• Types of extraneous variables

  1. Participant variables: age, intelligance, sex, ethnicity
  2. Situational variables: experimental surrounding settings
  3. Experimenter variables: personality, appearance of experimenter
• Demand characteristics


  When the participant can guess the aims of the experiment and lead to them changing behaviour to conform to expectations.

  They might: please the researcher by giving the 'right' responses, sabotage the researcher, acting unnaturally
• Investigator effects


  Researcher unconsciously influence results

  • Experimenter bias
  • Physical characteristics and personality
• Double blind procedures: when the experimenter AND participant dont know what condition they are in to reduce investigator effects

  Single blind procedures: when only participant dont know what condition they are in to reduce demand characteristics
• Laboratory experiments

  Well controlled environment with standardised procedures. Participant are randomly allocated to experimental groups

  • PROS: high level degree of control of IV AND DV that can be operationalised, replication to check results
  • CONS: low ecological validity- results cannot be generalised to real life setting, experimenter bias
• Field experiments

  Conducted in real life setting and manipulating IV but still keeping all variables controlled as possible

  PROS: high ecological validity, controlled IV

  CONS: loss of control that can lead extraneous variables affecting results, ethical- no informed consent
• • Natural experiment- IV varies/changes naturally and it isnt deliberately manipulated. Natural occuring event e.g weather
  • Quasi experiment- IV occurs/happens naturally that cannot be changed. Unable to freely manipulate IV e.g gender
• Observational techniques- involves watching and recording behaviour.

  • Particpant observation- observer becomes ACTIVELY INVOLVED in the situation
  • Non particpant observation- observer ARENT INVOLVED in behaviour studied
• Behavioural categories should be agreed amongst other observers, reflect whats being studied and be consistent. Done in letters, numbers etc.

  Inter-observer reliability is when observers consistently code behaviour in the same way to lessen chance of observer bias. Need to be clearly defined and no overlap
• Correlation studies 


  Assess and measure the relationship and direction between 2 co-variables. Use scattergrams

  • Positive correlation- when one co variable increases the other increases too. Goes up. Correlation coefficent of more than 0
  • Negative correlation- when one co variable increases the other decreases. Goes down. Correlation coefficient of less than 0
  • No correlation- no relationship found between co-variables. Random scatters. Correlation coefficient=0
• Evaluation on correlation studies

  • Pros: can be used when the experiment may be unethical, allows predictions to be made, allows quantification of relationship
  • Cons: doesnt show cause and effect relationship only an association between co-variables, extraneous variables may affect co-variables
• Questionnaires- self report technique where participants record their own answers to a pre set list of questions without a researcher present

  Interviews- self report technique where participants answer questions in face to face situations to a researcher
• Closed questions- simple and range of fixed responses. Easy to quantify but restricts participants answers e.g yes/no.

  Open questions- answers are detailed and greater depth but harder to analyse.
• Evaluation of questionnaires

  • Pros: lack of investigator effects, replication of questionnaires, quick and easy, quantitative and qualitative analysis of answers
  • Cons: low response rate, social desirability answers as people might lie to give whats expected, misunderstanding of the question
• Structured interviews: same standardised questions being asked in particular order to candidates. Quantitative data

  Unstructured interviews: Can ask follow up questions to explore answers. Questions arent prearranged. Qualitative data

  Semi structured: mixture of structured and unstructured.. Produces qualitative and quantitative data
• Evaluation of interviews

  • Pros: avoid misunderstandings, easy replication for structured interview, both qualitative and quantitative data produced in semi structured so easy analysis
  • Cons: interviewer effects affect answers like appearance, interview training to carry out unstructured interview, unsuitable for participants who cant put their feelings into their answers, unethical