JFI Commentary

[Charles Parker]

I do not know if anyone has read the commentary in the most recent JFI titled "Subjective"--The Misused Word by William Leo.

I just have one thing to say WOW. In eight pages Bill Leo has made me do a 180 degree turn. Made me flip my coin to the other side.

Very articulate and well written. I should have figured out to use the Law Definition instead of the Lay definition. It would have saved me a lot of grief (How Come I Did Not Think Of That---Oh Well).

Way to go Mr. Leo. I have always liked your writings (except for one which I shall not name) BUT the other 25 are GREAT, and this one is just WOW.

Good job.

[Gerald Clough]

Where does that really get us on reliability?

The critical question of subjective/objective is largely (but not entirely) one of input, rather than process. Selection of input, the analysis, includes decisions on the determination of the image area to be analysed and the identification of minutiae as impressions of actual physical features. Does the area to be used, even if broken or with featureless portions, represent a coherent portion of a single impression? Which minute marks represent features of some portion of skin?

The proper definitions really turn on the inclusion and exclusion of "externally verifiable." Indeed, this could BE the definition, if we take externally verifiable to mean generally vertifiable by verifiers outside some local set whose members might share a bias, prejudice, or interest.

Is the analysis externally verifiable? It is the product of human perception and judgment. Indeed, it is evident from cases that verification does not always follow such judgments. But (and I'll mature this point at the end), it is verifiable.

If all the observers agree to the nature and limits of a portion of image to be taken as representing a single impression, and if we all agree with the identification of a set of minutiae (and with the idcentification of artifacts), we can each proceed by a strictly objective, virtually mechanical, process of comparison. Is the comparison verifiable? If we are truly in agreement on the nature of the impression, it is verifiable.

Is the conclusion verifiable? It is, and a large number of analysts, given the determinations made in the analysis stage, will verify.

It makes little difference that in almost every case the analysis is so certain that it would be met by universal agreement. Every analyst believes in his analysis. Concluding from the products of an uncertain analysis is fraud, which is entirely another matter. The question is, what do we do about the cases in which there may not be agreement on analysis, with the cases where the conclusions of multiple examiners were found to be in error? Specifically, what do they mean to the discipline as a whole?

If the issue is reliability, what does that mean? Black's does not define "reliable." We find some interesting things in the common definitions. One is that they often refer to consistency. Another is that it suggests getting the same result in successive trials. Consistency does not exclude some errors. A succession of trials does not guarentee the same result in the next trial. It is contrasted with "infalible," which suggests complete absence of error, breakdown, or poor performance. At the very least, we cannot claim infallibility, if only on the issue of poor performance.

So, if objectivity can be established by the answer to the question, "Can your conclusions be verified?", the answer is that the examination is objective. We need not ask, "Will every expert verify every conclusion?" If that was the requirement for objectivity, much scientific knowledge and technical practice would be deemed subjective and unreliable.

[Thomas Taylor]

It seems to me that the whole argument that what we do is "objective," not "subjective," stems from the fear that subjective=unreliable and objective=reliable. When I'm hit with the defense argument in court that my opinion is "subjective," I readily agree that a conclusion of any kind is "subjective." But a subjective decision resulting from a careful examination by a trained, experienced expert is still highly reliable.

Mathematics might be defined as the most objective of all sciences, yet we make subjective decisions in applying the simplest manuevers of mathematics -- addition and subtraction. Those subjective decisions mean that occasionally we can't balance our bank statement. But if we are careful and double check our math, we can resolve things. Likewise, in fingerprint comparison, we can resolve things with a careful examination, the conclusion of which is verified. That renders the identification reliable.

Subjective does NOT mean "unreliable." The refusal by some to admit that anything about fingerprint comparison is subjective detracts from our credibility in court. Of course the decision making process is subjective! But being "subjective" makes our decisions no less reliable.

[Les Bush]

Hi Charles,

Because we are way down below the equator the IAI journal takes a while to turn up on the door step. Having read the article I was left in a place between the legal definitions and scientific definitions of these two terms. The bottom line is that when we arrive at court the conclusion we reach is expressed as an 'opinion', hence it is very subjective. The point in an examination where we utilise our experience to make a conclusion is based on a combination of factual evidence (linear relationships that are very objective requiring little interpretation) and a holistic evaluation (combination of factual evidence and appearance assessments). That point of 'sufficiency' will always be subjective and varies between each expert. The best example I can think of to illustrate this is the McKie case where the subjective conclusions highlight the very need for a truly objective (factual evidence) process that must support the holistic evaluation. Overall it was worth the wait and I support Mr Taylors final comments, very true! Cheers from oz.

[Charles Parker]

On a different forum (philosophy) there is a debate on Objective/Subjective. Here is the link. Be advised it is quite long so you need to take a pot of coffee.

http://forum.darwinawards.com/index.php?showtopic=8567

If this does not work go to Darwin Awards and then to the Philosophy forum on that site.

[Les Bush]

Hi Charles,

I had a look and it doesnt take long to see that educated humans will always have an opinion but rarely will they reach a consensus. To release ourselves from their debate we cross over into the technical component of our discipline. We are faced with an objective reality, the question being do the patterns of two fingerprints have a common source? Our objective knowledge is that the permanence and uniqueness of all human fingerprints is a principle that has been affirmed and can be relied upon. The experience of millions of examinations has established that no two persons have identical fingerprints and that falsifiability of the principle is possible but yet to be proved untrue. So we have two safeguards to begin our examination. The reality of the question posed about common source is unknown and must be resolved using careful observations and accurate application of the principles/rules of examination. Using similarity, sequence and spatial configuration we arrive at sufficieny and moment of recognition. Our conclusion is based on deductive reasoning and the application of subjective logic. Regards.

[Charles Parker]

Hi Les, I hope things are going well in Oz.

it doesnt take long to see that educated humans will always have an opinion but rarely will they reach a consensus.

I have not see a more accurate statement in a long time.

But for me I am staying away from the Philosophically corundum or Scientifc dilemma of Objective/Subjective and going with Bill Leo's article and using the Legal Definition when I am in court. It is objective.

Now out in the open air we can all fall back to the Philosophical or Scientific meaning of each and drive each other mad and see if we can beat the odds and come to a consensus (which I doubt).

Keep on plugging.

Cheers from the Lone Star State.

[RL Tavernaro]

I find myself in general agreement with Messrs. Leo & Parker, in the sense that under the law definition the process is defensible as objective. I also like the term "professional judgment" (as quoted in the JFI commentary) as a means of indicating that external influences shape the decisions & conclusions reached.

Of course, external influence may include bias, & I have difficulty in interpreting that as anything but subjective. Reliability & consistency require that the truly objective elements of the process be utilized in such a manner that they overcome any potential for bias.

IMHO, demonstrating the objective criteria that is relied upon is key. In the McKie and Mayfield cases, charts were prepared to demonstrate 'identifications'. However, those buckets were full of leaks and could not hold water. Placing numbers and lines to non-existent or mis-placed ridge features cannot hold up to objective scrutiny. The very 'proof' pro-offered in support of the 'identifications' instead provides actual proof of the contrary.
Regards, RLT