Engineers New to being Expert Witness -- Scientific Method
DISCLAIMER: I am not a lawyer and anything written here is strictly my opinion and should not be taken as legal advice.
Once upon a time, the Courts in the U.S. would accept testimony from anyone who claimed to be an expert. So, courts would listen to the carefully worked out horoscope from an astrologist as well as the results of a exacting chemical experiment. There was no real distinction made.
Then came Frye v. United States in 1923, Court of Appeals in the District of Columbia. Here was a case where the use of blood pressure as a means of lie detection was submitted as evidence. The judge threw the evidence obtained this way out of the court as it was not an accepted criteria amongst the experts in the field. This case created the test for expert testimony: is it generally accepted in the scientific community for which it applies. This eliminated the lunatic fringe from testifying in court. Hurrah! Some rigor must be used in collecting evidence, evaluating and testing it. The principles the conclusions are drawn on must be generally recognized as valid in the field.
Thus it has become important to courts to get their evidence based on the Scientific Method. There are various forms to the Scientific Method depending on who you ask or how it is defined, but basically it is
a. Recognizing a problem or question exists.
b. Collecting information, data, and observations about it.
c. Analyzing the information
d. Make a hypothesis which explains known data and observations
e. Test the hypothesis. (If it fails then go back to 'b' with your results)
f. Make a final hypothesis which explains all known or observed phenomena
and test results.
When you are preparing for a case, that is the touchstone they will be using to determine your qualifications and your findings--can you cast your information in to a form which shows you followed this method, are your data acquired through scientifically rigorous means and are your conclusions based on accepted rinciples.
There are other criteria involved in being an expert witness, of course, but this is one of the key points to be aware of in preparing.
I will be writing more on other case law and the application to being an expert witness.
Once upon a time, the Courts in the U.S. would accept testimony from anyone who claimed to be an expert. So, courts would listen to the carefully worked out horoscope from an astrologist as well as the results of a exacting chemical experiment. There was no real distinction made.
Then came Frye v. United States in 1923, Court of Appeals in the District of Columbia. Here was a case where the use of blood pressure as a means of lie detection was submitted as evidence. The judge threw the evidence obtained this way out of the court as it was not an accepted criteria amongst the experts in the field. This case created the test for expert testimony: is it generally accepted in the scientific community for which it applies. This eliminated the lunatic fringe from testifying in court. Hurrah! Some rigor must be used in collecting evidence, evaluating and testing it. The principles the conclusions are drawn on must be generally recognized as valid in the field.
Thus it has become important to courts to get their evidence based on the Scientific Method. There are various forms to the Scientific Method depending on who you ask or how it is defined, but basically it is
a. Recognizing a problem or question exists.
b. Collecting information, data, and observations about it.
c. Analyzing the information
d. Make a hypothesis which explains known data and observations
e. Test the hypothesis. (If it fails then go back to 'b' with your results)
f. Make a final hypothesis which explains all known or observed phenomena
and test results.
When you are preparing for a case, that is the touchstone they will be using to determine your qualifications and your findings--can you cast your information in to a form which shows you followed this method, are your data acquired through scientifically rigorous means and are your conclusions based on accepted rinciples.
There are other criteria involved in being an expert witness, of course, but this is one of the key points to be aware of in preparing.
I will be writing more on other case law and the application to being an expert witness.
Labels: California, Electrical Fire, Expert Witness, Forensic Engineering, San Diego
posted by Derek Geer - Forensics at
11:12 AM
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