El dualismo de la ideología colonial en tela de juicio

The use of FACS gives a testable set of variables to directly contrast quality across media. If one does not show the same level of detail then the visual display of facial movements will be lower, therefore, affording a lower level of behavioural representation for facial expressions.

6.3

Critical evaluation

6.3.1 Literature review

Due to the research area being multidisciplinary, it required the literature review to cover a large variety of subjects. This review was fascinating but it did not allow the same level of rigour as a review focusing solely on one topic. The review was also impacted upon by the change in direction from animals to humans which, although interesting, added further work. However, changes in research focus are common as new and exciting areas open up during the course of study. In addition, looking at a wide spread of literature is a necessity for this kind of study in order to encapsulate all the areas needed for the research.

6.3.2 Experiment 1: Gross behaviour identification – a comparison of video and CGI for the identification of Chimpanzee behaviour.

There are two reasons why a comparison of CGI and video for identification of behaviour is relevant. Firstly, observations of human or animal behaviour are mainly conducted in person or by watching video recordings. Virtual environments offer a free viewpoint update as in real life. A fair comparison of the qualities of virtual environments and real world for the identification of behaviour is not possible as people and animals do not display behaviour on command, therefore, the media cannot be matched. In order to overcome this issue, video observations were recorded and equivalent CGI footage created. This separation of the interactive experience allows the visual medium to be tested in isolation removing any confusion in future studies as to whether the results obtained are due to interactive or visual differences, thus allowing a fair isolated comparison of visual media. This is a similar

approach to that of Ragan et al. (Ragan et al., 2012) who are also studying the impact of individual qualities of virtual environments.

Users did perform well when identifying behaviours so there was enough realism for the task set out. However, for a serious training application, such a level of realism as that given in this study may not be enough; it should be possible to identify an aggressive walk or subtle facial expressions that can precede displays of violence. Simply put, users need to be able to understand intent. For obvious reasons it was not possible to facially track Chimpanzees. It is, however, possible to track a human and if it was proved feasible to reproduce subtle human behaviours then other primate behaviours would also be viable.

The experiment required participants to fill out a questionnaire declaring whether they had identified a particular behaviour. With hindsight, it would have been useful to record exact numbers either by using a clicker or by an audio recording of participants. It would also have been useful to conduct the study a second time with the same participants at a later date. This would have allowed for the study of knowledge retention and the learning of behaviours in addition to identification.

6.3.3 Experiment 2: Lie detection – a comparison of video and 3D video for the detection of deception.

In an ideal scenario it would have been preferable to capture video, authored abstract and virtuality representations of the participant (sender) simultaneously. However, hardware issues (such as occlusion) prevented this from happening. This would have allowed a direct comparison of the same data set. The comparisons provided are with a small number of past studies which would have had varying experimental designs and setups. However, the study

is still able to highlight what appears to be a suggestion that avatars lacking facial expression display a considerably higher truth bias than normal. Further studies are needed in this area to draw firm conclusions.

6.3.4 Experiment 3: Facial Action Coding – a comparison of video frames and 3D video frames regarding the quality of facial features and expressions.

The original aim was to compare video, abstract avatars and video based 3D reconstructed avatars. However, as previously discussed, facial capture for abstract avatars requires a camera to be close enough to the face to capture facial movements. This would have occluded facial capture using video based 3D reconstruction and, therefore, it was decided to compare video and the relatively new medium of 3D reconstruction as both could be captured simultaneously using a new experimental design that allowed timings and quality to be matched to allow a fair comparison. This does mean, however, that a further study will be necessary to identify whether current methods of mapping facial muscle movements to authored abstract avatars are sufficient to adequately represent behaviour. It would also be desirable to put a much larger number of images through this process and perhaps go to a more granular level in order to identify exactly which points of the face appear to be most affected by reconstruction. However, the study does highlight the lower face as being particularly problematic which fits in with the known problem of droop and, overall, the experiment shows no significant difference between the numbers of facial action units identified.