research methods

• Null hypothesis


  A general statement that the observed variables will have no impact as there is no relationship between them
• Alternative hypothesis


  A prediction that one variable will affect the other
• Formulating hypotheses


  1. Operationalise the independent variable and dependent variable

  2. Form a suitable alternative hypothesis

  3. Form a null hypothesis
• Independent variable (IV)


  What researchers manipulate in order to test its effect on the dependent variable
• Dependent variable (DV)


  The outcome or effect we are measuring within the study
• Extraneous variable


  A third variable that may unknowingly be affecting the outcome of the study (the DV)
• Sampling methods


  • Random sampling
  • Opportunity sampling
  • Systematic sampling
  • Stratified sampling
• Random sampling


  • All members of the target population have an equal chance of being selected
  • Reduces investigator effects
• Opportunity sampling


  • Fastest and easiest way to gather participants
  • Greater chance of being biased
• Systematic sampling


  • Simple way to gather participants
  • Little risk of research bias
• Stratified sampling


  • Very representative of the target population
  • Time-consuming to execute
• Volunteer sampling


  People that have volunteered to take part in the study
• Volunteer sampling


  • Participants should be willing to give informed consent
  • Volunteers may be a biased sample
• Experimental designs


  • Independent group design
  • Repeated measures design
  • Matched pairs design
• Independent group design


  • Participants divided into two subgroups, one exposed to the IV, one control group
  • No order effects
• Differences between groups in an independent group design may be due to participant variables rather than the IV
• Demand characteristics


  Behaviour displayed by participants that is different in response to the purpose of the study, which can invalidate findings
• Independent group designs


  • Participants are only exposed to one condition and they don't have the opportunity to learn or adjust their behaviour in another condition (as they cannot compare)
• Repeated measures design


  All the gathered participants of the study being exposed to both conditions of the experiment
• Matched pairs design


  Gathering participants and testing them prior to the study on certain characteristics to match them in pairs with someone similar
• Laboratory experiments


  Experiments conducted in a controlled setting, usually a research laboratory where participants are aware of being observed and part of a study
• Field experiments


  Conducted in a more natural or everyday environment, unlike the laboratory experiment where the behaviour being measured is more likely to occur
• Natural experiments


  Conducted when ethical or practical reasons to manipulate an independent variable are not possible, so the IV occurs 'naturally'
• Structured interviews


  All participants are asked the same pre-set questions in the same order, with the researcher unable to ask additional questions
• Unstructured interviews


  Participants are free to discuss anything freely, with the interviewer devising new questions as the interview progresses
• Questionnaires


  Used to collect large amounts of information from a target group, with respondents answering the same pre-set questions
• Questionnaires


  Practical ways for researchers to gather large amounts of information very quickly on topics where the responses are best suited for yes or no responses
• Questionnaires


  • They can be replicated very easily as all the questions are pre-set
  • Responses can be gathered again to check for reliability and validity
• Problems with questionnaires


  • Questions can be unclear or suggest/lead respondents into a desirable response
  • Responses can be affected by social desirability bias so participants may not answer truthfully
  • Respondents can only answer yes or no which limits the amount of information that can be gathered
  • Respondents may misunderstand the meaning of questions and answer incorrectly
• Case study


  A very detailed study of the life and background of either one person, a small group of people or an institution or an event
• Strengths of case studies


  • They provide detailed information about individuals (or target group/institution) rather than collecting a score on a metric test
  • They collect information over a long period of time so changes in behaviour can be observed and comparisons are drawn
• Weaknesses of case studies


  • They target a single individual making it difficult to generalise the findings to others
  • The data collected is very subjective and relies on people's perceptions and memories
  • The researcher may project their own biases onto the findings
  • There can be ethical concerns about informed consent
• Observational study


  The researcher watches or listens to the participants engaging in whatever behaviour is being studied and records their behaviour
• Strengths of observational studies

  • They are high in ecological validity and suitable for social behaviours as they allow researchers to gauge people's true responses
  • The behaviours observed have higher external validity as they can be more easily generalised
• Weaknesses of observational studies


  • Researchers do not know why the behaviour happened, requiring them to make judgements which may be biased
  • Participants may change their behaviour when aware of being observed
  • Researchers may make mistakes recording the behaviour
  • Ethical issues around informed consent
• Behavioural categories


  Systems used to make sure accurate records of behaviour are made
• Inter-observer reliability


  When two observers independently observe the same targets and compare their record sheets to check for consistency
• Correlation


  A relationship between two variables
• Types of correlations


  • Positive correlation
  • Negative correlation
  • Zero correlation
• Positive correlation


  One variable has a direct impact on the other, they increase together