In Trouble v. The Wet Seal, Inc., the United States District Court for the Southern District of New York examined the standards for admissibility of expert testimony in a trademark infringement action.

Plaintiff, Agnes Trouble, a French fashion designer, alleged in her complaint that defendant, The Wet Seal, Inc., was selling a line of clothing and accessories which infringed plaintiff’s AGNES B. trademark. In support of her claim, plaintiff sought to offer expert testimony on three subjects: (1) consumer confusion; (2) plaintiff’s expansion strategy; and (3) damages. Defendant moved to exclude the testimony as speculative and unreliable.

The district court analyzed the proffered testimony using the criteria set forth by the United States Supreme Court in Daubert v. Merrell Dow Pharmaceutical. Daubert established that a court must act as a “gate-keeper” to ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable. In Daubert, the Supreme Court identified five, non-exclusive factors to be used in determining whether an expert’s reasoning and methodology are reliable: (1) whether the theory or technique on which the expert relies has been tested; (2) whether the theory or technique has been subject to peer review and publication; (3) the known or potential rate of error of the technique or theory when applied; (4) the existence and maintenance of standards controlling the technique’s operation; and (5) whether the theory or method has been generally accepted by the expert community.

Applying the Daubert test, the district court in Trouble concluded that plaintiff’s expert witness was not sufficiently reliable to testify on two of the three subjects for which his testimony was being offered. With respect to consumer confusion, the court found that plaintiff’s expert, a former executive in the retail field, lacked any experience assessing likelihood of confusion and had based his conclusion, in part, on a simple comparison of products and store appearances. Such an analysis, the court noted, “is something the average trier of fact can perform without the assistance [of the expert].” The court similarly found plaintiff’s expert lacking on the subject of damages, since his analysis was “entirely based on the budgeted expenses of one store in a shopping mall in California.” An estimation based on so limited a sample amounted to “pure speculation.”

In contrast, the court denied the motion to exclude plaintiff’s expert testimony on the issue of plaintiff’s expansion strategy. The court noted that plaintiff’s expert had examined relevant documents provided to him by plaintiff and his opinion, “based on his former experience as an executive of a major chain of retail clothing stores, is sufficiently reliable and relevant to be admissible.”

In sum, when seeking expert testimony, it is critical that the expert’s credentials and methodology be sufficient to withstand court scrutiny.