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Court rejects the testimony of Human Factors Engineering Expert Witness after concluding jury cannot receive appreciable help from her “inconsistent” testimony 

Posted on November 16, 2023 by Expert Witness Profiler

The case in question involves a lawsuit filed by the Plaintiff, Clyde Arterburn, against Home Depot U.S.A., Inc. (referred to as Home Depot) for injuries sustained when he tripped and fell in a Home Depot store on September 21, 2020. According to the documents, Arterburn claims that he tripped over a metal basket holder that had been placed over a slightly protruding pipe as he was exiting the store. Home Depot argues that the basket holder was intended to hold baskets, not to cover the pipe, although there were no baskets in the holder at the time of the incident. The area where Arterburn walked and tripped over the basket, between a yellow bollard and a wall, was wide enough that he was able to pass through without twisting or adjusting his body in any way, and there were no signs or warnings in the vicinity to alert customers. 

Plaintiff’s expert witness, Joellen Gill, reviewed various materials, including photographs of the incident location, Home Depot’s supplemental discovery responses, and deposition transcripts of involved parties. In her report, Gill concluded that the incident area, between the yellow bollard and the wall, constituted a foreseeable pedestrian walkway around 40 inches wide. She noted that typical aisles and walkways usually had a minimum width of 36 inches. Gill estimated the wire basket’s height at 13.75 inches using the assumption that it was a quarter of the bollard’s height, which was 55 inches, without direct measurement. She reviewed and testified about Home Depot’s internal policies and procedures regarding keeping the aisles clear of tripping hazards and the use of merchandising displays. She observed that individuals tend to focus their visual gaze toward their intended destination rather than on the ground in their immediate vicinity. Gill discussed safety measures that Home Depot could have implemented to prevent similar incidents in the future. 

Home Depot filed a Motion to Exclude the Testimony of Joellen Gill, while Clyde Arterburn opposed this motion.  

Human Factors Engineering Expert Witness 

Joellen Gill, CHFP, CXLT, CSP holds a BS in human factors engineering from Georgia Tech and Wright State Universities, earned in 1979. With nearly four decades of experience, she spent 15 years in aerospace and national defense as a human factors engineer focused on safety and risk management. In 1994, she began employment with Applied Cognitive Sciences, a consulting firm specializing in human factors engineering, particularly safety and risk management and went on to become the owner/president of Applied Cognitive Sciences in 2018.

Joellen Gill is a Certified Human Factors Professional and boasts additional credentials as a licensed tribometrist and a Certified Safety Professional, underscoring her expertise in the field.

Discussion by the Court  

The Court engaged in a detailed discussion and analysis of various factors pertaining to the admissibility of expert testimony: 

The Court initiated its discussion by addressing the qualifications of the expert, Joellen Gill. It noted that Federal Rule of Evidence 702 requires that a witness be qualified as an expert based on knowledge, skill, experience, training, or education. The Court emphasized that the Rule 702 allows for a broad conception of expert qualifications and that only a minimal foundation of knowledge, skill, and experience is required. It pointed out that a lack of particularized expertise goes to the weight of the testimony, not its admissibility. The Court assumed Ms. Gill was qualified as an expert, indicating that her qualifications were not a point of contention in the case. 

The Court then shifted its focus to the reliability of the expert testimony. It detailed the factors outlined in Daubert v. Merrell Dow Pharms., Inc., a landmark case that established the standards for assessing the reliability of expert testimony. These factors included whether the expert’s method, theory, or technique is generally accepted within the relevant scientific community, whether the method has been tested, subjected to peer review and publication, and the known or potential rate of error of the method. The Court made it clear that the test for reliability was not about the correctness of the expert’s conclusions but the soundness of their methodology. It further explained that reliability required some objective, independent validation of the expert’s methodology. 

The Court emphasized the necessity of a connection, or “fit,” between the expert testimony and the issue at hand in the case. It noted that an expert’s testimony should provide appreciable help to the trier of fact and that expert testimony is inadmissible if it concerns issues within the knowledge and experience of ordinary lay people. 

The Court pointed out that, in this case, the central question was whether Joellen Gill’s expert testimony met the criteria for admissibility outlined in Rule 702, specifically focusing on relevance and reliability. 

Moving on to the issue of relevance, the Court examined whether Joellen Gill’s testimony would assist the jury in understanding the evidence or determining a fact in issue, as required by Rule 702. Home Depot contended that her opinions were well within the knowledge and experience of ordinary laypeople and therefore were not necessary. The Court agreed with Home Depot, asserting that the vast majority of Gill’s opinions about foreseeable pedestrian walkways, Home Depot’s policies, and customer behavior were common knowledge and did not provide appreciable help to the jury. 

The Court stressed that the jury should be able to draw its conclusions regarding the safety of the basket holder at Home Depot based on their own normal life experiences. It indicated that jurors would likely have visited similar stores, used similar shopping baskets, and generally had awareness of shopping basket holders’ locations, making Gill’s testimony redundant and irrelevant. 

Home Depot contested the relevance and reliability of Gill’s testimony regarding whether the Plaintiff traversed a foreseeable walkway, highlighting her alleged error in identifying the width of the chosen walkway. They pointed out that the 40-inch measurement referred to the distance from the bollard to the wall, not the actual space between the bollard and the white cabinet, which was the pertinent area. Defendant argued that the area Gill claimed was a “pedestrian walkway” had a cabinet located against the wall providing a visual cue that people should not walk there. The Plaintiff’s response to this challenge was considered inadequate by the Court. The Plaintiff cited Gill’s reliance on measurements provided by her assistant and referenced the Plaintiff’s deposition testimony, indicating that the white cabinet was further back at the time of the incident. However, the Court found it hard to accept Gill’s acceptance of the 40-inch measurement for the walkway while also relying on the photo to determine facts about that specific area. The Court criticized Gill’s estimation of the basket’s height at 13.75 inches, seemingly based on visual approximation from the photo where the basket seemed to occupy a significant portion of the space between the bollard and the cabinet. The inconsistency in Gill’s testimony about the walkway rendered it irrelevant in the Court’s assessment. The Court concluded that Gill’s testimony appeared unreliable, leaning on subjective belief or unsupported speculation, without needing to rule on the specific width of the walkway. 


The Court granted Home Depot’s Motion to Exclude Testimony of Plaintiff’s expert Joellen Gill. The Court issued a final ruling on October 20, 2023 dismissing the action without prejudice.

Key Takeaways:

  • Reliability Standards: The Court applied the standards outlined in the Daubert case to assess the reliability of expert testimony. These standards emphasize the necessity for the expert’s methodology to be based on sound science, subject to testing, peer review, and known error rates. Expert opinions should rely on proper methods and procedures rather than subjective belief or unsupported speculation. 
  • Relevance and “Fit”: Expert testimony must have a valid scientific connection or “fit” with the issues in the case. The Court highlighted that expert testimony should provide appreciable help to the trier of fact. In this case, it was observed that the jury should be able to draw its own conclusions on matters within their common knowledge and experiences, making Gill’s testimony redundant and irrelevant. 
  • Inaccuracies and Inconsistencies: The Court also considered inaccuracies and inconsistencies in the expert’s analysis as factors that further undermined the reliability and relevance of her testimony.