research methods

• Independent variable


  The variable that is manipulated by the researcher
• Dependent variable


  The variable that is measured
• Extraneous variable


  A variable (other than the IV) that might affect the DV
• Confounding variable


  A type of extraneous variable that you did not control for that does interact with the IV and affect the DV
• Operationalisation of variables


  Drawing out the most relevant elements of the variables so we can measure them
• Demand characteristics-

  The tendency of participants to work out how the experimenter expects them to behave and act accordingly
• Investigator effects


  • The researcher exerting an influence, either consciously or unconsciously, on the outcome of the research
• Laboratory experiment


  • Direct manipulation of an independent variable
  • High levels of control to control extraneous/confounding variables
  • Randomisation of participants and other factors
• High levels of control in laboratory experiments

  Increases internal validity but reduces ecological validity
• Demand characteristics in laboratory experiments

  Reduce internal validity as they mean the DV may not be a true reflection of behaviour
• Field experiment


  • Carried out in the natural environment
  • Researcher still manipulates IV and measures DV
  • Attempts to control extraneous variables as much as possible
• Field experiments


  Have higher ecological validity but lower control over extraneous variables compared to laboratory experiments
• Natural experiment


  • Takes advantage of naturally occurring events over which the researcher has no direct control over the IV
  • Participants are already assigned to a condition of the IV
• Natural experiments


  Have high ecological validity but limited opportunities to observe the desired behaviour and less control over extraneous variables
• Quasi-experiment


  • Uses a pre-existing IV that does not vary, so participants are not randomly allocated to conditions
• Repeated measures design


  • All participants take part in all levels of the IV and the results of the DV in both conditions are compared
• Independent groups design


  • Participants are split so that different participants take part in different levels of the IV, and the results of the DV from each group are compared
• Matched pairs design


  • Different participants are used in each level of the IV but they are matched as much as possible on key characteristics that are likely to influence the DV
• Factors to consider in experimental designs

  • Order effects
  • Number of participants
  • Participant variables
  • Demand characteristics
• Ways to deal with limitations of experimental designs

  1. Counterbalancing to control order effects

  2. Randomly allocating participants to conditions to distribute participant variables

  3. Conducting a pilot study to identify key matching variables

  4. Using independent groups to reduce demand characteristics
• Interviews


  • Aim to gather information about what people (interviewees) know, feel and/or do about a particular topic
  • Provide a natural and flexible approach to questioning
• Interview structure


  1. Structured

  2. Semi-structured

  3. Unstructured
• Structured interviews


  Interviewees are asked the same set of standardised questions in the same order
• Semi-structured interviews


  Interviewer may use some of the same questions for all interviewees, but there is flexibility in the order, whether they are asked at all and, sometimes, in how questions are phrased
• Unstructured interviews


  More informal, the purposeful conversation about the topic of interest is allowed to unfold in its own way
• Checklist for planning interviews

  • Have you stated the aim of the interview?
  • Have you clearly described the research question?
  • Have you generated an appropriate set of questions?
  • Have you planned the order in which the questions will be presented?
  • Have you planned the interview to obtain the required balance between structured and unstructured interviewing?
  • Have you identified and approached potential respondents?
  • Have you decided how the information is to be recorded in the interview?
  • Have you considered the ethical issues raised by the proposed research?
  • Have you considered your non-verbal communication and listening skills?
• Strengths of interviews


  • May lead to more accurate data being gathered
  • May lead to more detailed data being gathered
• Limitations of interviews


  • Can be hard to analyse
  • Interpersonal variables can affect the interaction between the interviewer and respondent
• Correlation


  Analysis of the relationship between co-variables
• Correlation


  • Calculates a correlation coefficient, a statistic that has a value between -1 (perfect negative correlation) and +1 (perfect positive correlation)
  • Correlations are usually plotted onto a scatter plot so you can visually see whether the relationship is positive, negative or if there is zero correlation
• Positive correlation


  As one variable tends to increase, so does the other
• Negative correlation


  As one variable tends to increase, the other decreases
• Zero correlation


  Shows no relationship between the two variables
• Experiment


  The experimenter deliberately manipulates the impact each condition/level of the IV has on the DV
• Correlation


  No deliberate change is made to any variable, the impact of one variable on another is not being tested, just the relationship between co-variables
• Strengths of correlations


  • Can indicate the direction and strength of the relationship between two variables
  • Allow researchers to statistically analyse situations that could not be manipulated experimentally for ethical or practical reasons
• Limitations of correlations


  • Do not establish cause and effect, only a relationship between two variables
  • Cannot measure non-linear relationships
• Pilot study


  A small scale study, carried out with a restricted number of participants who will not take part in the study itself, before the process of collecting data begins
• Issues to be identified in a pilot study

  • Experiments: Confounding/extraneous variables, whether materials used are suitable, whether timings are appropriate, whether standardised instructions are clear
  • Observations: Whether behavioural categories are clear and unambiguous, whether timing and CCTV are correct, whether sampling technique is appropriate
  • Interviews: Whether extraneous variables are controlled, whether questions are clear and understandable, whether recording methods are suitable, quality of the interviewer, structure of the interview
• Benefits of a pilot study

  • Increase validity - measuring what you set out to measure
  • Increase reliability - ensuring the data is recorded in the same way
  • Save time - won't waste participants' time