Research methods

• Experimental method


  A method of investigation used to demonstrate cause-and-effect relationships by purposely manipulating one factor thought to produce change in another factor.
• Laboratory experiments


  experiments conducted in a lab, a highly controlled environment
• Field experiments


  experiments conducted in natural settings rather than in the laboratory
• Natural experiments


  Naturally occurring events or phenomena having somewhat different conditions that can be compared with almost as much rigor as in experiments where the investigator manipulates the conditions.
• Quasi experiments


  comparisons of groups that differ in exposure to a variable of interest that cannot be manipulated for ethical or practical reasons 'almost experiments
• Naturalistic observation


  observing and recording behaviour in naturally occurring situations without trying to manipulate and control the situation
• Controlled observation


  Some control over variables takes place to observe how people may interact/behave. They take place inside and outside of a lab.
• Overt observation


  Participants know they are being observed
• Covert observation


  Participants do not know they are being observed until after the observation
• Participant observation


  investigators systematically observe people while joining them as participants
• Non-participant observation


  when the researcher observes behaviour without participating in that behaviour
• Questionnaire


  a written set of questions to be answered by a research participant
• structured interview


  a research procedure in which all participants are asked to answer the same questions
• Unstructured interview


  no fixed set of questions and no systematic scoring procedure

  involves asking probing questions to find out what the applicant is like
• Correlation


  A measure of the relationship between two variables
• Aims


  The purpose of the investigation
• independent variable


  a variable that is manipulated by the experimenter
• Dependent variable


  the outcome factor; the variable that may change in response to manipulations of the independent variable.
• Operationalise


  Ensuring that variables are in a form that can be easily tested.
• Hypothesis


  a precise, testable statement of the relationship between two variables
• Directional hypothesis


  a one-tailed hypothesis that states the direction of the difference or relationship
• Non-directional hypothesis


  two-tailed hypothesis - simply states that there is a difference but not what the difference will be.
• Target population


  a group of people that share similar characteristics and are identified as the intended audience for research
• Random sample


  a method of selecting from a population in which each person has an equal probability of being selected
• Opportunity sample


  a sample of participants produced by selecting people who are most easily available at the time of the study.
• Stratified sample


  a sample drawn in such a way that known subgroups within a population are represented in proportion to their numbers in the general population
• Systematic sample


  a sample drawn by selecting individuals systematically from a sampling frame
• Bias


  a predisposition to a certain point of view despite what the facts suggest that may influence a study
• Generalisation


  the application of the results from a study, to the wider target population
• Pilot study


  a small study carried out to test the feasibility of a larger one
• Independent groups design


  an experimental design in which different groups of participants are exposed to different levels of the independent variable
• Random allocation/Randomisation


  allocating participants to experimental groups or conditions using random techniques
• repeated measures design


  an experimental design where the same participants are used in all the conditions in an experiment.
• Counterbalancing


  a method of controlling for order effects in a repeated measure design by including all orders of treatment (ABBA)
• Matched pairs design


  an experimental design where pairs of participants are matched on important characteristics and one member allocated to each condition of the IV
• Open questions


  questions that allow for a variety of extended responses
• Closed questions


  questions that can usually be answered with yes or no.
• Extraneous variables


  any variables other than the independent variable that seem likely to influence the dependent variable in a specific study
• Confounding variable


  a factor other than the independent variable that might produce distorted associations between two variables
• Order effects


  occur when the order in which the participants experience conditions in an experiment affects the results of the study