Issues relevant to the suspect, lies and videotapes study

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The application to everyday life (its usefulness)

The study by Mann et al is one of the most useful psychological studies ever. Police are trained to look for lying behaviour when conducting interviews but on what basis? This study suggests this training is wrong. Instead police should be trained to look for longer pauses and a decrease in eye blinking.

2. Ecological Validity

High in ecological Validity.

16 Suspects were being interviewed by real police in a real police interview room

Suspects had a genuine reason to lie because if they were convincing they would not be charged with the crime they were accused.

Authentic high- stake liars.

3.Ethics

There was no informed consent - Participants were not aware their videotape would be used in a study

Since participant was not aware - there wouldn't be deception, harm done, right to withdraw and debriefing but there was confidentiality - participants were not named

4. Reliability

The study had 2 observers to check the reliability of the observations.

Mann et al found very high inter-rater between the 2 observers. eg: for gaze aversion the correlation was 0.86, blinking - 0.99 and for speech disturbance 0.97

5. Validity

Validity is high - as they were real suspects telling real lies to try to avoid punishment and possibly going to prison - she used authentic high stake liars

6. Qualitative and Quantitative data

Structured observation - the researcher designed a coding scheme to record the participant behaviors - gaze aversion, blinking, arm and hand movements, pauses, speech disturbance and head movements

It allowed direct comparisons to be made in their behaviours

It was scientific and objective

Snapshot study

It was an hour long videotape consisting of 45 video clips - took place at just one point

Quantitative data produced - so statistical analysis is possible

PEE paragraph for each, saying how the issue relates to Mann et al and giving examples from the study.

P - "One issue with the study by Mann et al is __________"

E - "An example of this in the study is __________________"

E - "This is an advantage/disadvantage because _________________"

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