Definitions

• Experimental method


  Involves the manipulation of an independent variable to measure the effect on the dependent variable. Experiments may be laboratory, field, natural or quasi
• Aim


  A general statement of what the researcher intends to investigate, the purpose of the study
• Hypothesis


  A clear precise, testable statement that states the relationship between the variables to be investigated. Stated at the outset of any study
• Directional hypothesis


  States the direction of the difference / relationship
• Non-directional hypothesis


  Does not state the direction of the difference or relationship
• Variables


  Any 'thing' that can vary or change within an investigation. Variables are generally used in experiments to determine if changes in one thing result in changes to the other
• Independent variable


  An aspect of the experimental situation that is manipulated by the researcher – or changes naturally- so the effect on the DV can be measured
• Operationalisation


  Clearly defining variables in terms of how they can be measured
• Extraneous variable


  Any variable other than IV which might affect the DV if not controlled. Nuisance variables that don't vary systematically with IV
• Dependent variable


  The variable that is measured by the researcher. Any effect on the DV should be caused by change in the IV
• Confounding variable


  An EV that varies systematically with IV. We can't tell if change in DV is because of IV or the CV
• Demand characteristics


  Any cue from the investigator or from the research situation that may be interpreted by participants as revealing the purpose of the investigation. May lead to participant changing their behaviour within the research situation
• Investigator effects


  Any effect of the investigators behaviour (conscious/unconscious) on the research's outcome
• Randomisation


  Use of chance method to control the effects of bias when designing materials and the order of experimental conditions
• Standardisation


  Using the same formalised procedures and instructions for all participants in a research study
• Experimental design


  The different ways participants can be organised to the experiment's conditions
• Independent groups design


  Participants allocated to different groups where each group represents one experimental condition
• Repeated measures


  All participants take part in all experiment conditions
• Matched pairs design


  Pairs of participants are first matched in some variable that may affect the dependent variable. Then one is assigned to condition A and one to condition B
• Random allocation


  Attempt to control participant variables in an independent group design which ensures that each participant has the same chance of being in one condition as the other
• Counterbalancing


  Attempt to control order effects in repeated measures design – half participants experience the conditions in one order and the other in the opposite order
• Lab experiment


  Takes place in a controlled environment where the experimenter manipulates the IV and records the effect on the DV, while maintaining strict control of extraneous variables
• Field Experiment


  Takes place in natural setting where the researcher manipulates the IV and records the effect on DV
• Natural experiment


  Change in IV is not brought about by the researcher but would have happened even if the researcher had not been there. Researcher records the effect on the DV they have decided on
• Quasi experiment


  Almost an experiment, IV has not been determined by anyone – the variable simply exists already, e.g. gender or age. Not technically and experiment
• Population


  Group of people which are the focus of the researcher's interest, from which a smaller sample is drawn
• Sample


  Group of people who take part in a research investigation. Drawn from a target population and is assumed to be representative of that population
• Sampling techniques


  Method used to select people from the population
• Bias


  In regards to sampling, when certain groups are over or underrepresented within the sample – limits extent of generalisation to target population
• Generalisation


  Extent to which findings from a particular study can be broadly applied to the population
• Pilot Study


  Small scale version of an investigation before the real one is conducted. Aim is to check that procedures materials work and to allow the researcher to make necessary changes
• Naturalistic observation


  Watching and recording behaviour in the setting where it would normally occur
• Controlled observation


  Watching and recording behaviour within a structured environment – where some variables are managed
• Covert observation


  Participant's behaviour is watched and recorded without their knowledge
• Overt observation


  Participant's behaviour is watched and recorded with their knowledge
• Participant observation


  Researcher becomes a member of the group they are observing
• Nonparticipant observation


  Researcher remains outside the group whose behaviour they are observing
• Behavioural categories


  When a target behaviour is broken into components that are observable and measurable (operationalisation)
• Event sampling


  Target behaviour/event is first established then researcher records the event every time it occurs
• Time sampling


  Target individual/group is first established – then researcher records their behaviour in a fixed time frame