Chapter 4 Basic Methodology Flashcards
The basic methodology of the fire investigation should rely on the use of
a systematic approach and attention to all relevant details.
With few exceptions, the proper methodology for a fire or explosion investigation is to first
Determine and establish the origin, then investigate the cause: circumstances, conditions, or agencies that brought the ignition source, fuel and oxidant together.
What are the steps of the Scientific Method
Recognize the need (identify the problem)
Define the problem
Collect data
Analyze the data
Develop a hypothesis (inductive reasoning)
Test the hypothesis (deductive reasoning)
Select final hypothesis
Analysis of the data is based on the
knowledge, training, experience, and expertise of the individual doing the analysis.
The investigator does not have a valid or reliable conclusion unless:
The hypothesis can stand the test of careful and serious challenge.
Testing of the hypothesis is done by the principle of
Deductive reasoning, in which the investigator compares the hypothesis associated with the phenomena relevant to the specific incident.
Any hypothesis that is incapable of being tested either physically or analytically,
is an invalid hypothesis.
________ is a well established phenomenon that occurs in scientific analysis when investigators reach a premature conclusion without having examined or considered all the relevant data.
Expectation bias
Different hypotheses may be compatible with the same data. When using the scientific method, testing of hypotheses should be designed to
disprove the hypothesis.
Confirmation bias occurs when:
the investigator tries to confirm the hypothesis.
The fundamental purpose of conducting an examination of any incident scene is to
collect all of the available data and document the incident scene.
The goal of all investigators is to:
arrive at accurate determinations related to the origin, cause, fire spread, and responsibility for the incident.
The investigator should know the level of certainty that is required for providing expert opinions. Two levels of certainty commonly used are
probable and possible
This level of certainty corresponds to being more likely true than not. At this level of certainty, the likelihood of the hypothesis being true is greater than 50%.
Probable
At this level of certainty, the hypothesis can be demonstrated to be feasible but cannot be declared probable. If two or more hypotheses are equally likely, then the level of certainty must be “possible.”
Possible
