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Welcome to the Forensic Multimedia Analysis blog (formerly the Forensic Photoshop blog). With the latest developments in the analysis of m...

Tuesday, May 31, 2011

Photoshop 12.1 = Photoshop 12.0.4

This just in from Adobe's John Nack: "What’s the difference between Photoshop CS5 and 5.5? Nothing besides subscription support. Here’s some concise clarification from Jeff Tranberry:

Photoshop CS5 (Version 12.1 – which comes as part of Creative Suite 5.5) and Photoshop CS5 (Version 12.0.4 – a free update for the version of Photoshop which came as a part of Creative Suite 5) are exactly the same in terms of functionality except that 12.1 will support a subscription license.

Both contain the same updates to fix issues, both have the same camera support with Camera Raw 6.x, and both work with the Photoshop Touch Apps."


Monday, May 23, 2011

G-mail hacked

Sorry for the long delay. The g-mail account that is used to facilitate this blog was hacked. Thankfully, Google was able to resolve the issues ... it just wasn't as timely as I'd hoped.

That being said, I wasn't in the London Embassy in need of everyone to wire me cash to Nigeria ...

I do appreciate the e-mails of concern.

The blogging will resume soon ...

Thursday, May 12, 2011

Medical examiner may not be immune to bias

From the Durango Herald: "Should forensic scientists know as little or as much as possible about the facts of the underlying case?

An article from the University of California, Irvine, school of law addresses this question and presents the following anecdote:

An evolutionary biologist studying the lineage of the Australian finch utilizes DNA testing to determine whether more brightly colored males mate more and produce more young and whether the male in a bonded pair is always the father of his partner’s offspring.

The biologist is adamant that DNA test results must be examined blind (the scientist can’t know, for instance, which birds are a bonded pair when determining offspring lineage) because it’s human nature to seize upon evidence that supports the investigator’s hypothesis and minimize or discredit evidence to the contrary.

Because the danger of bias is well-known, a scientist using less rigorous procedures would never be able to obtain financial support or publish in peer-review journals, the biologist says.

“You must understand that this work is extremely important,” she said. “It affects our understanding of the entire evolutionary history of the finch!”

The interpretation of forensic evidence often has a major influence on the outcome of criminal prosecutions, so it’s extremely important, too, but rarely do forensic scientists interpret evidence blind.

They usually know the basic facts and nature of the case, and they understand how their determinations will influence the investigation and the likelihood of successful prosecution.

Decades of psychological studies have made it clear that contextual bias is a fundamental part of human decision-making rather than a moral failing, that people are unaware to a remarkable degree of the extent to which context influences them and that they are not able to eliminate these biases by rigorous training or force of will.

Most scientific disciplines take great care to eliminate contextual bias, and the argument that it poses no problem for criminalists working in labs is becoming less credible (especially since a 2010 report of the National Academy of Sciences on the forensic sciences).

Still, most people don’t admit that contextual bias might be a problem for medical examiners.

Are they not physicians? Should they not be privy to all information? Does anyone think doctors should focus only on physical examinations and be kept ignorant of context when making diagnoses? Of course not.

But there’s a basic difference between forensic and clinical medicine that people rarely consider: When a doctor is trying to figure out if a patient has heart trouble or indigestion, no moral considerations create bias by favoring one diagnosis over the other.

When a medical examiner is convinced by circumstantial evidence that some low-life has killed a child, it’s morally right to do everything possible to support the prosecution.

When she’s convinced by circumstantial evidence that an innocent man has been wrongfully accused or imprisoned, it’s morally right to do everything possible to exonerate him.

Are medical examiners able to reliably ignore these sorts of contextual biases when interpreting autopsy findings?

Don’t bet the farm ..."

Continue reading by clicking here.


Tuesday, May 10, 2011

Not all experts know things in exactly the same way

"...In the summer of 1999, the United States Supreme Court issued the last in a trilogy of 1990s cases dealing with the question of the admissibility of expert testimony in federal courts. In Kumho Tire Co. v. Carmichael, the Court was asked to decide if the judicial gatekeeping role it set forth in the first of these three cases, Daubert v. Merrell Dow Pharmaceuticals, applied only to "scientific" knowledge or to all expert testimony. The court concluded that all expert testimony must be both relevant and reliable before it can be admitted, but that the specific factors set forth in Daubert to judge the reliability of scientific evidence may be supplemented and perhaps replaced by other factors when expert testimony is based on "technical" or "other specialized" knowledge. The opinion explicitly recognized that not all expert testimony can be judged by a single standard because not all experts know things in exactly the same way ..." - From Kumho and how we know by Joseph Sanders.


Monday, May 9, 2011

Toward an Ethics of Expertise

"... The relationship between expert and layperson is grounded on an epistemic inequality. The expert knows more than the layperson about matters within the scope of her expertise. And if the layperson appeals to the judgment of the expert, he usually does so because he acknowledges the superiority of the expert's judgment to his own. Thus, the epistemology of the expert-layperson relationship can be focused on the concept of rational deference to epistemic authority. This rational deference lies at the heart of the particular form of power that an expert has and is also the center of the particular form of vulnerability that each of us, as a layperson, is in.

The concept of rational deference presupposes that the layperson appeals to the expert and acknowledges the rational authority of the expert. Obviously, someone must appeal to the expert, some layperson must acknowledge the authority of the expert or the expert's knowledge will be socially irrelevant and useless. So, the ideas of appealing to epistemic authority and rational deference may suffice for the epistemology of expertise. But when we turn to the ethics of expertise, we must not forget that often an expert's expertise is applied to those who have not appealed to the expert. They may well not even agree that this opinion represents a form of expertise. Indeed, expert opinion alters many people's lives without their knowledge, much less their consent ..." - From Toward an Ethics of Expertise by John Hardwig


Friday, May 6, 2011

The Advocate for a Cause

"Although the courts sometimes invoke the dangers of the "professional witness" and the "hired gun," the real legal problems with expert testimony are more subtle. Even the most vehement critics of litigants' use of scientific expert testimony acknowledge that litigants usually do not need to influence their experts. On the contrary, a litigant usually can find an expert who will express the view that the litigant wants to have expressed. 79 Nor does this necessarily suggest that the expert is biased, even if the testimony is a minority view: "Some of these experts are undoubtedly motivated by financial concerns; others may simply possess eccentric viewpoints ..." - From Conflicts of Interest in Scientific Expert Testimony by Mark R. Patterson


Thursday, May 5, 2011

The "Hired Gun"

"It is certainly true that the testimony of a "hired gun"--or, as some courts put it, an expert who is "available to the highest bidder"-is not "scientific knowledge" and therefore should be inadmissible under Daubert. Given the frequency (and vehemence) with which this danger is invoked, especially in the popular press, one might expect it to be a frequent focus of the courts. In fact, though, courts are seldom concerned about this issue, presumably because, as Daubert II recognized, "few experts appear in court merely as an eleemosynary gesture." One cannot use the mere fact that an expert is paid by his client as a basis for inferring that his testimony is biased; one must look more carefully at the expert's testimony to determine if it is biased, and once one makes that further inquiry, one is not relying on the premise that the expert is a "hired gun." - From Conflicts of Interest in Scientific Expert Testimony by Mark R. Patterson


Wednesday, May 4, 2011

The "Professional Witness"

"An expert who is a "professional witness" is not necessarily biased. Courts most often use this term to describe an expert who "spends substantially all of his time consulting with attorneys and testifying." Independent of any bias such an expert might have, spending all of his time testifying will inevitably erode his scientific skills and knowledge, and he will become less qualified to opine on the subject of his (former) expertise. A court rightly might refuse to admit the testimony of such a witness because "he' is more a professional witness than an expert." Strictly speaking, though, the court would not be rejecting the witness's testimony itself; the court instead would be deciding that the proposed witness is not qualified as an expert at all.

No issue of bias necessarily exists here, at least on the part of the witness. It is true that if a "professional witness" is one who lacks real scientific competence, he may be more likely to testify for the party whose position is less scientifically accepted, because that party will find it more difficult to hire competent experts. That does not show that the witness is biased, though, or that his testimony is false. It instead might be that "professional witnesses" can be found with a wide range of views, so that the only bias in their use is in the universal selection by parties of witnesses that will support their positions." - From Conflicts of Interest in Scientific Expert Testimony by Mark R. Patterson


Tuesday, May 3, 2011

Conflicts of interest

"Sources of bias in scientific expert testimony can be divided into three categories. The first does not, strictly speaking, involve conflicts of interest on the part of the experts, but it is nevertheless a source of bias: parties to litigation control both the testimony presented and, often, the scientific research that is the basis of that testimony. For example, an interested party might select experts who will present testimony favorable to the party's point of view rather than purely objective testimony, or it might choose to fund only research that it believes will reach results favorable to its position. The second problem is a more traditional conflict of interest: the inclination of experts to give testimony that favors a party or position in which the experts have a financial interest. The third problem is the possibility that the underlying research record itself may be distorted by conflicts of interest." - From Conflicts of Interest in Scientific Expert Testimony by Mark R. Patterson

Monday, May 2, 2011

Hiring an expert

Here's something to consider when hiring an expert who may eventually testify in court for your case:

"That an expert testifies based on research he has conducted independent of the litigation provides important, objective proof that the research comports with the dictates of good science. For one thing, experts whose findings flow from existing research are less likely to have been biased toward a particular conclusion by the promise of remuneration; when an expert prepares reports and findings before being hired as a witness, that record will limit the degree to which he can tailor his testimony to serve a party's interests. Then, too, independent research carries its own indicia of reliability, as it is conducted, so to speak, in the usual course of business and must normally satisfy a variety of standards to attract funding and institutional support. Finally, there is usually a limited number of scientists actively conducting research on the very subject that is germane to a particular case, which provides a natural constraint on parties' ability to shop for experts who will come to the desired conclusion."
Daubert v. Merrell Dow Pharms., Inc., 43 F.3d 1311, 1317 (9th Cir. 1995)