LEC10 Scientific Methodology in Forensic Science PDF

Scientific Methodology in Forensic Science LEC10 – Friday October 11th FRSC2030H Foundations in Forensic Science  LAB03 Forensic Anthropology Due Dates ODD Lab Section – Friday October 18th 2359 EVEN Lab Section - Friday No...

Scientific Methodology in Forensic Science LEC10 – Friday October 11th FRSC2030H Foundations in Forensic Science  LAB03 Forensic Anthropology Due Dates ODD Lab Section – Friday October 18th 2359 EVEN Lab Section - Friday November 1st 2359 Course Update Feedback for Labs NO CLASS Monday October 14th! “Crime Stories” Uncertainty Present throughout experiments Experimental design Measurement error Accuracy of results Reasoning Science can provide some answers Common-Sense vs Scientific Reasoning Scientific Method “forensic scientists have regularly testified in court to matters that are, quite honestly, both less proven and less certain than they are claimed to be. They have overstated their degree of knowledge, underreported the chances of error, and suggested greater certainty than is warranted. More generally, many kinds of forensic science are not entirely based on the methods and approaches that we usually associate with validated research science.” - Mnookin (2010) Methods of Inquiry Method of authority Expert source Point of view or experience Rational method Logical reasoning Scientific method Sources, deductive reasoning, and falsification Builds upon itself Knowledge vs Information Knowledge Skills & experience Information Facts of the situation Evidence Based Practise Guidelines 1. Formulate answerable questions 2. Use the best evidence to answer questions 3. Critically appraise the evidence for its validity and usefulness 4. Integrate this appraisal with expertise and apply it in practise 5. Evaluate the implementation of performance Goudge Report (2008) Dr. Charles Smith Forensic Pathologist at Hospital for Sick Kids (1982-2003) Performed 1000 child autopsies 2002 reprimanded 2003 removed Review Examined 45 autopsies 9/45 disagreed 20/45 problems (12 guilty) Goudge Report (2008) 169 recommendations: Certification in Canada, recruit & retain experts Funding Require best practices Relay objective truth Connect with other experts Independently reviewable/transparent Understandable to courts Evidence-based, not experienced-based analysis System-based oversight Scientific Method in Forensic Science Science is a method Scientific method is a tool used in science Observation, hypothesis, predictions, methods, investigation, results, discussion Not the same in all fields Observations in Forensic Science Observations Passive Observations Active Observations Reasoning What explains observed data Theory to predict observations Compared with predictions  Types of Reasoning Deduction Induction Abduction 1. Theory 1. Observation (or Retroduction) 2. Hypothesis 2. Pattern 1. Observation 3. Observation 3. Hypothesis 2. Hypothesis 4. Confirmation 4. Theory 3. Theory Aristotle Sherlock Holmes Everyday Scientific Reasoning All scientific theories/laws need to be falsifiable! (Popper, 1959) Positive result cannot confirm Negative result refutes “Positivism” Tentative until further science conducted Multiple hypothesis (Hempel, 1967) (Lakatos, 1997) Falsify and determine best one Hypothetic-deductive reasoning Cyclical pattern of observations & results