Marketing Expert’s Post-Sale Confusion Survey is Admissible
Posted on July 8, 2025 by Expert Witness Profiler
Think Green Limited (“Think Green”) has taken Medela AG and Medela LLC (“Medela”) to Court, accusing them of infringing on the trade dress rights it holds in its breast pump and misleading consumers through false advertising.
Rhonda J. Harper, a Think Green expert witness in areas involving marketing, branding, and consumer research, used various analytical methods to conclude that (1) among the relevant universe of consumers, there is a likelihood of confusion that Medela’s pump is sponsored or approved by Think Green due to the allegedly infringing trade dress; and (2) the relevant universe of consumers would likely ascribe secondary meaning to Think Green’s trade dress. Medela filed a motion to exclude Harper’s expert opinions and underlying survey results pursuant to Rule 702 and the Daubert Standard. Medela also sought to strike Harper’s rebuttal declaration.
Cynthia Cohen, who Medela proffered as an expert in areas related to psychology and consumer research, reached the following conclusion based on her analytical work: “offering the Medela breast milk collector on the Amazon platform does NOT cause consumer confusion.” Think Green filed a motion to strike this conclusion and the entirety of Cohen’s expert report.
Think Green also filed a motion to strike portions of the expert report prepared by Medela expert Carsten Faltum.
Marketing Expert Witness
Rhonda Jane Harper has over 30 years of experience at the highest levels of marketing, research, and branding. She has been the top marketing executive for several Fortune 100 corporations, served as an adjunct marketing professor at two universities, held national and international board positions in leading brand and marketing associations, led a leading global agency division, and founded an organic growth strategic consultancy. Harper has also provided and rebutted hundreds of trademark and trade dress infringement surveys for litigation purposes.
Psychology Expert Witness
Cynthia R. Cohen, Ph.D. is an expert in survey methods. She designed consumer studies for Lanham Act cases and change of venue surveys for trials. Cohen’s education includes psychology degrees at UCLA and USC. Her firm, Verdict Success LLC, specializes in in jury research, trial strategies, and settlement decision-making.
Life Science Expert Witness
Carsten Faltum has extensive experience in the life sciences industry, particularly in R&D coupled with several years as an investment manager in venture capital and corporate venture.
Discussion by the Court
Rhonda Harper
Admissibility of Survey Evidence, Generally
With regard to Harper’s surveys, Medela argued that the data was not analyzed in accordance with accepted statistical principles, nor was the objectivity of the entire process assured.
Courts generally find consumer survey evidence admissible if a qualified expert testifies that the survey was conducted according to generally accepted principles of survey research. Moreover, survey evidence need not be perfect to be admissible.
The Court held that Harper’s surveys did not constitute one of those “rare” situations where fundamental flaws rendered them “completely unhelpful to the trier of fact and therefore inadmissible.”
Admissibility of Harper’s Survey Evidence
Control Stimuli in Secondary Meaning and Point-of-Sale Confusion Surveys
Medela took issue with the control stimuli Harper used in her secondary meaning and point-of-sale confusion surveys. Medela also objected to the pump images that members of both control groups were shown—in other words, the control stimuli.
The survey ultimately asked respondents whether or not “the manufacturer or brand of the breast milk pump/collector [they] just reviewed … is sponsored or approved by another manufacturer or brand.” If a respondent answered yes to the “sponsored or approved” inquiry, the respondent was then asked what other manufacturer or brand had sponsored or approved the pump or collector the respondent had just viewed and why the respondent thought so.
Medela argued that the control stimuli are “so wildly different” than the test stimuli that Harper’s surveys are unreliable.
But as Think Green pointed out, it is not imperative that secondary meaning surveys include a control group at all to be considered reliable. As at least one district court has observed, secondary meaning surveys measure the extent to which consumers associate a particular trade dress with a particular source, and a control group would not necessarily aid in that analysis. Nor is it clear that including a weak control stimulus (even assuming that is a fair characterization of the control stimuli used here) renders a survey “so flawed as to be completely unhelpful to the trier of fact” and therefore inadmissible.
According to the Court, Medela’s bones of contention provides no basis to strike Harper’s testimony altogether.
Point-of-Sale Confusion Survey and Marketplace Reflection
Medela separately complained that Harper’s point-of-sale confusion survey did not reflect how consumers encountered the depicted pumps in the real-world marketplace.
It argued that the pictures Harper used did not “present[] the full scope of information available to a prospective online purchaser” and were “devoid of a host of further identifying information that consumers would typically encounter by viewing the actual product listing page for these products.”
A survey need “not replicate the exact purchasing experience of every consumer confronting the pertinent product in the marketplace”; it requires only “reasonable choices based on the expert’s experience and training and on accepted survey techniques.”
In this Court’s estimation, Medela’s criticisms did not bear on the survey’s admissibility, but on the “evidentiary weight of the survey results”—a question for the jury.
Control Stimulus in Post-Sale Confusion Survey
Through a different survey, Harper sought to “determine whether Medela’s breast milk pump/collector is likely to cause post-sale confusion.” Post-sale confusion occurs when a potential customer sees a product bearing the Plaintiff’s trade dress and mistakenly attributes the product to the Plaintiff, thereby influencing his or her buying decision, either positively or negatively.
To assess the likelihood of post-sale confusion, Harper’s online survey first screened for respondents who purchased a pump in the last year or who would consider purchasing one in the next year. The test group was presented with four images of Medela’s pump, collected from Medela’s online retail product pages, less Medela’s name, design elements, and measurements.
Medela objected to the images Harper presented to the test group of its pump as well as the control stimuli images.
The Court held that a survey need not be excluded simply because it failed to use the best available control stimuli.
Test Stimuli in Post-Sale Confusion Survey
Medela next criticized the post-sale confusion survey’s test stimuli as failing to “reflect real-world conditions in which consumers are likely to encounter the products.”
What images Harper should have presented to better depict the “obvious intimate and exposed” nature of using a breast pump, Medela did not say. In any event, whatever Medela’s argument, the Court held that it affected the weight of the evidence—not its admissibility.
Test Stimulus in Secondary Meaning Survey
Medela argued that the test stimulus Harper used in her secondary meaning survey was “fundamentally flawed” because it failed to isolate the trade dress.
To support its assertion that “a secondary meaning test stimulus must isolate the trade dress at issue,” Medela cited Handelman’s Guide to TTAB Practice, Second Edition, § 18.15. However, the quoted portion of Handelman’s Guide specifically directs that “[i]f the image used in the stimulus differs from the mark shown in the application or registration drawing”—as Medela alleges here—”the difference will weigh against the probative value, if any, to be accorded to the survey.” In other words, the Court held that Medela’s own source instructed that the weight to be assigned to the secondary meaning survey is a question for the jury—not one of admissibility.
Use of Functional Stimuli To Assess Non-Functional Trade Dress
Medela next argued that Harper’s surveys did not test the asserted trade dress, because the “shield-bulb-base” arrangement featured in the stimuli is functional.
Because this argument mirrors a central theory of Medela’s summary judgment motion: that Think Green’s asserted trade dress is functional and therefore cannot be protected, the Court will address this argument when it resolves Medela’s motion for summary judgment.
Net Secondary Meaning Calculation
Medela argued that Harper’s secondary meaning calculation is “fundamentally flawed” because, in calculating net secondary meaning, she failed to subtract a particular number from the results.
Harper, however, has laid out her reasons for employing the methodology that she did and, in so doing, amply conveyed that her calculations were a considered choice, not the result of a fatal error or oversight.
At the end of the day, the two experts analyzed the same data, but came to different conclusions about its meaning. That leaves the Court with a “battle of the experts” situation that is inappropriate for dispensation in a Daubert motion and must be left for the factfinder to resolve.
Data Supporting Secondary Meaning Opinion
Medela argued that Harper’s report “fails to substantiate the connection between these data points with its conclusions that these were purportedly successful in connecting Think Green as the source of the trade dress in the minds of relevant consumers.” By “these data points,” Medela appeared to be referencing the entire universe of “sales data, advertising expenditures, awards, social media followers etc. ” in Harper’s report. But Medela did not actually cite to “these data points” or describe them with any degree of specificity. The Court will not guess at them, nor will it develop Medela’s argument for it.
Admissibility of Harper’s Rebuttal Declaration
Think Green attached a rebuttal declaration from Harper to its response to Medela’s motion for summary judgment in which Harper responded to Medela’s criticism of her net secondary meaning calculation. Medela filed a motion under Rule 37 to strike this declaration.
In her short rebuttal declaration, Harper responded to what she described as “mischaracterization” and criticism Medela offered in its summary judgment briefing. More specifically: Harper explained that there are multiple ways of calculating net secondary meaning and why she chose her particular method of calculation. At the conclusion of her rebuttal, Harper performed an alternate method of calculation that “[s]ome sources indicate [is] also appropriate,” which she claims—consistent with her previously expressed opinion—”shows that the trade dress is strong.”
The Court denied Medela’s motion to strike Harper’s rebuttal declaration because it remained “firmly grounded” in the opinions she expressed in her original expert report. Basically, Harper’s rebuttal declaration is the type of responsive report that is permitted under Rules 26 and 37.
Cynthia Cohen
Qualifications
Medela contended that Cohen’s experience conducting consumer surveys related to trademark disputes is relevant to trade dress disputes, as the methodology between the two topics is largely interchangeable. Medela also cited her publications, speeches, and court appearances as an expert witness concerning consumer surveys.
According to Think Green, Cohen’s limited prior experience as an expert or witness rendered her unqualified.
Despite criticizing Cohen for not having “essential” experience, education, or training in marketing, Think Green did not draw any link between “a professional marketing background” and trade dress likelihood of confusion surveys. The Court is not persuaded that an expert who lacks a marketing degree or marketing experience should be automatically precluded from opining on matters of trade dress.
Methodology
Think Green argued that Cohen’s likelihood of confusion survey relied on improper methodology. In Cohen’s survey, respondents were shown the stimulus image of Medela’s pump “as it had been displayed on the Amazon platform.”
With the stimulus picture still available on the screen, respondents were asked open-ended questions meant to assess whether confusion was likely. For example, respondents were asked “if you have an opinion, what company or organization makes or puts out this breast milk collector” and if the respondent had an opinion, whether the respondent “believed that this breast milk collector is affiliated with or sponsored by any other company.”
Think Green objected to Cohen’s methodology of showing respondents the stimulus picture while the respondents answered the survey questions. According to Think Green, this is “a major flaw” that “departs from typical marketplace conditions.”
As the Court already explained when denying Medela’s motion to exclude Harper’s expert report, no survey is “foolproof,” and perfection is not required to clear the Daubert bar. Think Green has presented no argument that any flaws in Cohen’s survey create one of the “rare” situations where a survey is so fundamentally flawed “as to be completely unhelpful to the trier of fact and therefor inadmissible.”
Relevance
Like Harper’s testimony, the Court held that Cohen’s survey evidence concerning likelihood of confusion will assist the jury in evaluating Think Green’s claim of trade dress infringement.
Carsten Faltum
As for Think Green’s motion to strike portions of the expert report prepared by expert Faltum, the Court denied Think Green’s motion to partially strike without prejudice to renewal after Think Green hinted that it may file a more robust motion to strike Faltum’s report before trial.
Held
The Court denied Medela’s motion to exclude Rhonda Harper’s expert opinions and underlying survey results as well as Harper’s rebuttal declaration. Think Green’s motion to strike Cynthia Cohen’s report was also denied by the Court.
Additionally, the Court denied Think Green’s motion to partially strike portions of Carsten Faltum’s report without prejudice to renewal.
Key Takeaways:
- A survey need “not replicate the exact purchasing experience of every consumer confronting the pertinent product in the marketplace”; it requires only “reasonable choices based on the expert’s experience and training and on accepted survey techniques.”
- Courts generally find consumer survey evidence admissible if a qualified expert testifies that the survey was conducted according to generally accepted principles of survey research. Moreover, survey evidence need not be perfect to be admissible.
- The notion that Daubert requires particular credentials for an expert witness is radically unsound. Anyone with relevant expertise enabling them to offer responsible opinion testimony helpful to judge or jury may qualify as an expert witness.
- In a case of dueling experts, it is left to the trier of fact—not the reviewing Court—to decide how to weigh the competing expert testimony.
Case Details:
| Case Caption: | Think Green Limited V. Medela AG Et Al |
| Docket Number: | 1:21cv5445 |
| Court Name: | United States District Court, Illinois Northern |
| Order Date: | July 02, 2025 |
