research methods

• Laboratory experiment 

  conducted in a highly controlled environment that is not familiar to the participant. The IV is manipulated by researchers and changes to the DV are measured
• scientific eval of lab experiment


  establishes a clear cause and effect relationship, scientific
• internal validity eval of lab experiment


  high internal validity, sure DV change is due to IV
• replicable eval of lab experiment 


  standardised procedures make it easily replicable
• ecological validity eval of lab experiment 


  lack ecological validity, cannot be applied to real world scenarios. Tasks are usually artificial and don’t reflect real life so they lack mundane realism which lowers external validity
• demand characteristics eval of lab experiment


  ppts know they are in a study so demand characteristics mean they may alter their behaviour (matching behaviour to the aim)
• Field experiment 


  conducted in a natural setting that is familiar to the participant
• ecological validity eval of field experiment


  ppts are more likely to act naturally in their natural environment which increases ecological validity
• demand characteristics eval of field experiment


  ppts do not show demand characteristics as they are usually unaware that they are taking part in a study
• mundane realism eval of field experimental


   more likely to have mundane realism as they are not artificial tasks
• random assign eval of field experiment 


   impossible to randomly assign ppts to different conditions meaning change in DV could be due to participant variables meaning internal validity is reduced.
• lack of control eval of field experiment


  lack of control over extraneous variables that could influence DV
• replication eval of natural experiment


   the events happen naturally and are often rare meaning it is unlikely that it would be possible to be replicated.
• Natural experiment 


  the level of the independent variable has already happened with no influence, the researcher simply record the change in the DV between the two IV
• opportunity eval of natural experiment


   allows research in areas that could not happen in controlled settings due to ethics or cost reasons
• external validity eval of natural experiment


  high in external validity, real life behaviour and no demand characteristics
• Quasi experiment 


  the IV is an innate characteristic that already exists in the ppt. ppts cannot be randomly assigned between levels of IV
• only way eval of quasi experiment


   only way to study factors that are pre-existing characteristics of ppts
• control eval of quasi experiment 


  may be other factors relating to the level of IV that cannot be controlled, change systematically and alter measurement of DV (confounding variables)
• Aim of a study 


  a general statement stating what is being studied and sometimes why but not ho
• Hypothesis


  Precise and testable statement including IV and DV
• Directional hypothesis 


  suggests that there is a difference between variables and states in which direction the difference will go
• Non directional hypothesis 


  suggests that there is a difference but not a direction
• Repeated measures


  The same ppts complete the two conditions (or more)
• order effects eval of repeated measures


  taking part in both conditions may mean that order effects such as boredom or fatigue may influence results
• demand characteristics eval of repeated measures


  ppts are more likely to figure out the aim due to demand characteristics
• Independent groups


  Different ppts are randomly allocated to each condition
• participant variable evaluation of independent groups


  random allocation means participant variables may influence results
• Matched pairs


  Different ppts are ranked on a characteristic and then paired and randomly allocated to each condition
• participant variables eval of matched pairs


   reduced participant variables as they are matched on characteristic
• order effects eval of matched pairs


  no order effects, one condition each
• time consuming eval of matched pairs


  time consuming and needs more participants
• similarity eval of matched pairs


  ppts are matched on similarities but they are not identical
• Independent variable 


  aspect of the experiment which has been manipulated by the researcher or simply changes naturally to have an effect on the DV (measured)
• Dependent variable


  aspect of the study which is measured by the researcher, caused by change to the IV
• Operationalisation


   researcher clearly defines how variables are being measured.
•  Extraneous variables 

  any other variable which is not the IV that effects the DV and does not vary systematically with the IV. 
• Confounding variables


  a variable other than the IV that has an effect on the DV and does change systematically with the IV. Makes it harder to be sure of the origin of the impact of the DV
• Demand characteristics 


  when the participant feels like they have guessed the aim of the study and acts differently in order to fit the aim.

  Please-U and Screw-U effects
• Investigator effects 


  any unwanted influence from the researcher's behaviour, either conscious or unconscious.