1. What data do Hare et al use? The data used were 3D topographical images of each bullet, an array of surface measurements (x3p format) and “x3pr” and “bulletr” R packages

  2. In what ways do the methods used by Hare et al differ from the “traditional” methods of bullet matching? In the traditional method, the bullets are placed under comparison microscopes and are manually analyzed by forensic scientists for comparison. The approach taken in the video used computing distributional differences between known matches and known non-matches using a reference database to match bullets.

  3. How do Hare et al use clustering to help perform bullet matching tasks? Random forest was used to help calculate error rate and therefore helped perform the bullet matching tasks within this research experiment. With this concept and using 300 trees for this situation, matches and non matches were able to be brought to light.

  4. Identify one statistics and/or probability concept in the presentation that you have not heard of before. Do a little bit of research (Googling/Wikipedia is ok) and try to describe it to someone who doesn’t know about it. You should also consult this paper to see if there is more detail on your chosen topic than is presented in the webinar. (Hint: Control + F is useful…) You don’t need to read the whole paper.

A statistics concept in the presentation that I had not heard of prior to the viewing of this video was that of cross correlation. Cross correlation is a statistical measurements that finds how similar in nature two different information sets are based on the relative displacement of each other.