Lab and Field experiments

• AO1 of Lab exp

  - Set in highly controlled artificial setting of police station, away from EW everyday environment such as prison

  - IV manipulated by police (leading Qs), DV is accuracy of EWT. Study of C+E involving 2 or more conditions e.g. leading or non leading

  - All extraneous variables aimed to be controlled such as how much of the setting is visible

  - Random allocation of EW to conditions of leading/non-leading q's

  - High control of environment of police station/same proc for all EW
• AO3 Eval of Lab

  :) Cause and Effect

  :) Standardised Procedure

  :( Lacks Mundane Realism

  :( Demand Characteristics
• :) Cause and Effect

  :) Lab exp of EWT set in highly controlled artificial setting of police station so extraneous variables such as how much of police station is visible can be controlled. T/f can make sure that manipulation of IV (leading/not) causes change in DV (accuracy of EWT) so can establish C+E, increasing val
• :) Standardised Proc

  :) use same standardised proc so same video of crime, and same questions on crime depending on if P is in leading/not leading condition. T/f increases reliability of lab exp to investigate EWT, can easily be replicated to establish consistent findings on accuracy of EWT
• :( Lacks mundane realism

  :( task such as watching vid clip of fake crime in a lab setting of police station is not accurate to everyday EWT of crime. T/f findings on accuracy of EWT are not naturally occuring, and cannot be generalised to a wider pop, thus decreasing val
• :( Demand Characteristics

  :( conducted in highly controlled artificial lab setting (police st) so EW aware they are being researched and noting accuracy of recall of crime viewing on video clip. May change answers and behaviour to how they think researcher wants them to act. T/f accuracy of EWT isnt naturally occuring, and EW causing accuracy of recall, not IV of leading/non, reducing val of lab exp for EWT
• AO1 Field exp

  - EW may see a crime that is likely to be staged

  - The EW may see a real crime occur and after the police have finished doing the official procedures, the researchers can manipulate the IV (leading questions or not)

  - An IV (leading/not leading) is manipulated by researcher to measure DV (accuracy of EWT)

  - Ex variables not controlled as EW view of setting may be diff (some closer to crime than others)
• AO3 Eval field exp

  :) Mundane Realism

  :) Eco Validity

  :( Low control

  :( Demand Characteristics
• :) Mundane Realism


  :) EW either witnesses a staged crime that they thought was real, or a real crime such as a mugging in a park, so accurate to EWT of everyday crime occurrences. T/f increasing the accuracy of recall of EWT so findings on crimes from EWT can be generalised to everyday court cases
• :) Ecological Validity

  :) conducted at a staged crime setting, or a real crime that is occuring in the EWs natural everyday environment. T/f accuracy of EWT naturally occuring, so info gathered from EWT can be generalised to everyday court cases
• :( Low control

  :( Conducted in natural setting for EW, where extraneous variables are difficult to control, such as the EWs proximity to the location of the crime. T/f C+E cannot be established between leading/non leading q's of researchers, and accuracy of EWT, decreasing the val of EWT
• :( Demand Characteristic

  :( If the setting of the crime is staged, EW may become aware that they are being researched, and that their recollection is being notes, so may change recall based on perception of police's questions. T/f decreasing the accuracy of recall during EWT, thus reducing the validity of information collected during EWT of a field exp
• Similarities between lab and field exp in crim

  - Demand characteristics (EW aware recall being noted to may change it)

  - Standardised proc - high reliability as same questions given to EW based on condition (leading/not)
• Differences between lab and field exp in crime

  - Lab is highly controlled artificial setting, can control ex variables, cant in field.

  - Field, EW can see naturally occuring crime, so has eco val