Forensic epistemology: exploring case-specific research in forensic science

Our inquiry into forensic epistemology explores the use of data types for case-specific research within three pattern interpretation disciplines. It also examines the epistemic status of practitioner case experimentation in forensic science. We developed three cases from different pattern-interpretation disciplines: a friction ridge analysis; a bloodstain pattern analysis; and a footwear impression analysis. For each case, a series of experiments were derived using three different data types: a quantitative approach (using numeric data), a qualitative approach (using image data) and a mixed-method approach (using both numeric and image data). We supplied data analyses that would be common knowledge for any academic researcher. Electronic files were compiled for each case and research method and forwarded by Qualtrics Software to forensic practitioners within the prescribed discipline. Demographic questions on practitioner education level and years of experience were included in the survey, along with open-ended comment areas. The dependent variable is the participants' percentage confidence in providing an opinion from the data type used. ANOVA analyses indicated that the practitioners were more confident using a mixed-method data approach. No differences were found between the percentage confidence levels and discipline type. Similarly, there was no significant difference between the confidence levels and years of experience or the participants' education level. The qualitative data analysis validated the quantitative results in that the practitioners were more confident with a mixed-method research approach.