Engineering Expert Excluded After Failing To Conduct Studies In Controlled Environment

Zach Barreto

Written by Zach Barreto

- Updated onOctober 25, 2023

Court: United States District Court for the Eastern District of New York
: Federal
Case Name
: Jensen v. Cablevision Sys. Corp.
: 372 F. Supp. 3d 95

In this case, the plaintiff purchased a WiFi connection and suffered financial and privacy damages after the connection was made publically accessible. In support of the plaintiff’s case, a mechanical engineering expert conducted calculations in electricity consumption to assess damages. However, the defense noted that the calculations demonstrated more errors than the industry standard. The court ultimately found that the study was not conducted in a controlled environment and thus, the results were affected by external factors and could not be considered reliable.


The plaintiff bought a WiFi connection from the defendant, Cablevision Systems Corporation, and he leased a router free of cost from the defendant. This router also included a separate public network that allowed other Cablevision subscribers in the vicinity of the plaintiff’s router to access its internet connection. The plaintiff filed a class certification suit claiming damages secondary to this public access including increased electricity costs, reduced speed, and violation of privacy. The plaintiff relied on the testimony of two experts, a professor of mechanical engineering at Yale University and an associate professor in the College of Information Studies at the University of Maryland, to support his claim.

The defendants moved to preclude the testimony of both the plaintiff’s experts on grounds that they were not qualified enough to testify as expert witnesses in the case as per the standard set by Daubert and that their testimony was not reliable or helpful.

The Experts

The plaintiff’s mechanical engineering expert had been a faculty member at Yale University since 1984. His accomplishments included membership in respected scientific and engineering societies, hundreds of academic publications and dozens of lectures at conferences, seminars, and symposiums. The expert restricted his report to calculating the difference in electricity consumption caused by using public WiFi network on the router along with a home network.


The defendants objected to the expert’s methodology of experimentation, making 5 criticisms: (1) the power meter used in the experiment is unreliable; (2) the study is not reflective of real-world customers; (3) the experiment was conducted in the expert’s residence rather than a controlled laboratory environment; (4) the readings were manually recorded by the expert; and (5) the expert used the highest energy usage for each 60-second period.

The court found that he was fit to be an expert witness in the case as he was a qualified mechanical engineer with enough know-how to conduct scientific and engineering experiments.

The court was of the opinion that the second objection only affected the weight of the opinion and not its admissibility. However, it agreed with the other four criticisms because the power meter used was demonstrated to have more errors than the industry standard, the study was not conducted in a controlled environment and thus results could be affected by external factors. The manual recording of more than 8,000 readings made the study highly susceptible to errors, and the use of highest energy usage for a time period was unreliable because of the reasonable possibility of the average value being lower than the highest energy value. Thus, the court noted that the expert failed to use “the same level of intellectual rigor that characterizes the practice of an expert in the relevant field,” citing Kumho Tire Co., 526 U.S. at 152.

Regarding the information systems expert, the court noted she was qualified enough to opine on the matter because of her work in the field of social media privacy issues. Her lack of specific knowledge in issues related to WiFi privacy issues affected the weight of her opinion and not its admissibility. The court noted that “An expert need not be precluded from testifying merely because he or she does not possess experience tailored to the precise product or process that is the subject matter of the dispute'” citing Hilaire, 54 F. Supp. 3d at 236 (quoting Yaccarino v. Motor Coach Indus., Inc., No. 03-CV-4527, 2006 U.S. Dist. LEXIS 97208, 2006 WL 5230033, at *9 (E.D.N.Y. Sept. 29, 2006)), and that lack of expertise in a specific area affects the weight of a testimony and not its admissibility, citing Hilaire, 54 F. Supp. 3d at 235-3. However, a part of her testimony was excluded as the court felt it rehashed otherwise acceptable evidence. The court also noted that the plaintiff failed to satisfy the conditions for class certification as laid down in Rule 23 of the Federal Rules of Civil Procedure.


The court excluded the mechanical engineering expert’s testimony, allowed testimony in part from the information systems expert, and denied the plaintiff’s claim for class certification.

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