Experimental Design: Bite Marks -
When approaching a study on bite marks and how they can be used in forensic science, it is vital that one takes into mind that there have been few studies done on the subject to date. In addition, those that have been done have not lead to much stock being put in the subject. With this in mind, I would propose a multi-step experiment that will be outlined below. The intention of the study is to focus on the inconsistencies that are present in bite mark analysis and to develop a criteria similar to those used by other examiners.
Experiment:
In order to design this experiment, one would have to do foundation research in order to identify the most common and the most commonly successful methods used when identifying bite marks. This knowledge will be taken and used as the basis for the experiments. Each of the styles of examination will be a different micro experiment with multiple trials. Each experiment will also be set up the same way and the results of each will, ideally, help to identify the best method to identify bite marks if indeed one does exist.
When setting up each of the individual experiments in this study, it is crucial that the conditions be the same in each situation. These include a skin stand in, mouth casts, bite simulator, and pressure that the simulator is set at. If each trial is to be comparable with the others there has to be a consistency. For this to happen, the settings on the machine must be consistent and the mouth casts must have exact duplicates in the case of damage.
Each micro experiment would involve a number of different mouth casts. The same number of bites and model(s) would be used across micro experiments (Units). Human bites would be inflicted along with a few animal bites. These bites will then be given to the examiners to study and identify. Each Examination method will be a treatment and the method if infliction and delivery will be consistent.
The responses from the treatments will be the notes and conclusions gained from those administering the identification styles. These would be measured based on accuracy and ability to correctly identify the bite marks. According to the given readings, the false positive rate in some cases is 1 in 6. While this would be difficult and take many replicates, this would set a basis for future studies as long as everything is kept consistent and biases are left out.
Randomness would be achieved through the assignment of bite to the examiners. Replication will be done by using each cast multiple times through each micro experiment.
Wrap:
The tricky part of this experiment would be getting the practitioners all trained to the same caliber on the different identification methods and getting them assigned to the samples. This is just a rough outline, but after finding the strong method, this could be a step in either setting this as a solid forensic method or putting it to rest as an un-useful field.