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Is PMI the Hypothesis or the Null Hypothesis?

NCJ Number
252415
Date Published
July 2017
Length
7 pages
Author(s)
Aaron M. Tarone, Michelle R. Sanford
Agencies
NIJ-Sponsored
Annotation
This article discusses the decades-old debate regarding whether forensic entomologists estimate the postmortem interval (PMI), minimum PMI, or something else.
Abstract
During the period of this debate, there has been a proliferation of terminology that reflects this concern regarding “what we do.” This has been a frustrating conversation for some in the community because much of this debate appears to be centered on what assumptions are acknowledged directly and which are embedded within a list of assumptions (or ignored altogether) in the literature and in case reports. An additional component of the conversation centers on a concern that moving away from the use of certain terminology like PMI acknowledges limitations and problems that would make the application of entomology appear less useful in court—a problem for lawyers, but one that should not be problematic for scientists in the forensic entomology community, since uncertainty is part of science that should and can be presented effectively in the courtroom (e.g., population genetic concepts in forensics). Unfortunately, a consequence of the way this conversation is conducted is that even as all involved in the debate acknowledge the concerns of their colleagues, parties continue to talk past one another advocating their preferred terminology. Progress will not be made until the community recognizes that all of the terms under consideration take the form of null hypothesis statements and that thinking about “what we do” as a null hypothesis has useful legal and scientific ramifications that transcend arguments over the usage of preferred terminology. (Publisher abstract modified)
Date Created: November 21, 2019