Frowd et al

Frowd et al

1. Aim

   • To study and understand the relative recognisability of internal and external features of facial composites.

2. Design

   • 3 laboratory experiments

3. Participants

   • Experiment 1:
     • 30 members of staff and students from Stirling University
   • Experiment 2:
     • 48 students from Stirling University
   • Experiment 3:
     • 8 members of staff and students from Computer Science and Psychology

4. Procedure

   • Experiment 1:
     • Independent Measures
     • The participants were shown 10 target photographs of famous people and 40 composite images produced by various computer programs.
     • There were 3 sets of composites used
       • A set of complete faces
       • A set of containing only internal features
       • A set containing only external features
     • The participants were randomly assigned to one of the three composite sets and tested individually
     • All the faces were clean shaven and faces with glasses were avoided
   • Experiment 2:
     • This experiment used a photo array to compare the quality of the external and internal composite features of Experiment 1. While more difficult to set up than a sorting task, as a number of distracter faces (foils) must be located for each target face, the photo array task may function more a measure of identification, such as police line-up given tha the arrays contain foils and targets deliberately selected to be similar to each other.
   • Experiment 3:
     • The results of both experiment one and two suggest that recall of faces focuses mainly on the external features. The problem with both sets of results was that causation cannot be inferred.

5. Results

   • Experiment 1:
     • Both the complete composites and external composites were sorted with similar results with around 35% correct. Whereas the internal composites were around 19.5% correct.
     • Experiment 2:
       • External composites = 42% correct
       • Internal composites = 24% correct
       • Experiment 3
         • Both complete faces and external composites were sorted with similar results with around 35% correct. Whereas the internal composites were around 19.5%