Expert Witnesses in Web Accessibility Cases (Part 1)

What is an expert witness? Well, an expert is someone who has a specialized kind of knowledge that may be relevant to a case. We’ve all seen crime dramas in which a scientist is cross-examined about an opinion she has offered that involves DNA testing or some other specialized piece of information.

Just having specialized information is enough to be an expert witness. For instance, an astrologer could tell the jury about the alignment of the stars and planets on the night of the murder—and suggest that this would make it highly unlikely that the defendant committed the crime because of the zodiac signs of the victim and the defendant.

To understand why this kind of expert testimony wouldn’t be allowed into a case, let’s look briefly at the history of how expert witness testimony has evolved. Going back to the 1923 case of Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), where a defendant was accused of murder. Before the trial, the defendant underwent a test to measure his blood pressure while being asked about the crime. The defendant’s expert would testify that scientific experiments showed that changes in systolic blood pressure are indicative of stress—and because the defendant’s blood pressure remained calm, his statements of his innocence were likely true. The court rejected the expert testimony because it was too experimental. Instead, the court noted that the expert testimony must “have gained general acceptance in the particular field in which it belongs.”

While the Frye standard is still used in several state courts and it was the standard that I learned in law school evidence class. But, like all things ancient, it has been replaced in most states and the Federal courts by the Daubert standard, which derives from the eponymous Supreme Court case, Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). In Daubert, the plaintiffs claimed that their birth defects were caused by the morning sickness medication Bendectin, which was taken by their mother during pregnancy and sold by the defendant. The plaintiffs claimed that laboratory and animal studies had showed that Bendectin causes birth defects, but these studies had not gained acceptance in the general scientific community. While the trial and appellate court excluded this evidence under the Frye standard, the plaintiffs argued that a more liberal standard should be applied because Congress had amended the Federal Rules of Evidence to potentially include evidence other than just scientific evidence that had “gained general acceptance” in the scientific community. Instead, the evidence needed to be useful scientific information that was developed through a scientific methodology or a scientifically valid reasoning.

Determining whether expert testimony followed a “scientific methodology” or a “scientifically valid reasoning” is the tricky part. You’ll often hear lawyers talk about the “five Daubert factors,” which courts weigh together to determine if expert testimony should be admitted. These factors are (1) whether the theory or technique has been tested, (2) whether it has been peer-reviewed, (3) what is the error rate for the technique, (4) whether standards or protocols exist and were followed, and (5) the level of widespread acceptance within the scientific community.

That sounds like a pretty tough standard—and it is! And, we’ll see how this can play out in web accessibility litigation next. Incidentally, while winning a case against a major pharmaceutical company before the Supreme Court may sound like a huge win, it wasn’t for Mr. Daubert. After the Supreme Court sent the case back to the appellate court, they dutifully applied the five Daubert factors and dismissed the case.

After the Daubert case, Congress again tweaked the Federal Rules of Evidence. Federal Rule 702 (Testimony by Expert Witnesses) now reads as,

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:

(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;

(b) the testimony is based on sufficient facts or data;

(c) the testimony is the product of reliable principles and methods; and

(d) the expert has reliably applied the principles and methods to the facts of the case.

Congress also noted that the Supreme Court did not intend the five factors in Daubert to be either exclusive or dispositive and noted that several other courts had used additional factors in determining the reliability of expert witness testimony.

So what's the bottom line when it comes to expert witnesses? Ultimately, expert witness testimony can be attacked on a number of grounds for asserting that it is unreliable. I think that most lawyers will try to base an attack on Daubert or the Rule 702 to keep things tidy (every lawyer likes to rely on a valid Supreme Court case whenever possible) but expert testimony can usually be attacked any number of ways if the opposing attorney thinks it is unreliable.