Likelihood of Confusion – Survey Basics

Expertise You Need + Experience You Want


Rhonda Harper has decades of experience providing independent and reliable consumer based survey research solutions. Her survey research informs litigators so that strategic case decisions can be made with confidence. Specifically, Rhonda Harper delivers consumer research and expert testimony for litigation in the areas of trademark infringement, likelihood of confusion, copyright, and other business-related disciplines. Harper's work has contributed significantly to favorable settlements and verdicts for clients across a broad range of industries.

Harper offers a wide range of services including custom designed research in the following areas:

• Likelihood of confusion • Strength of mark • Secondary meaning • Acquired distinctiveness • Lanham Act claims • Consumer perception • Consumer understanding

Harper is also regularly engaged to review and critique existing survey data put forward by opposing experts.

Two Basic Survey Formats

The majority of surveys under the Lanham Act address likelihood of confusion and the most used formats have been Eveready and Squirt.The differences between the Eveready and Squirt formats are:

  1. their opening questions;
  2. the means by which they replicate market reality, access brands, and facilitate inferences as to source;
  3. the confusion factors they measure; and
  4. the circumstances under which they may provide evidence supporting (or negating) a conclusion as to a likelihood of confusion.
Eveready Format

In 1976, in Union Carbide Corp. v. Ever-Ready, Inc., the Seventh Circuit endorsed Eveready in litigation involving the EVEREADY mark for batteries. Over time, it has become the "gold standard" in cases where the senior mark is strong, i.e., highly accessible in memory,  enhancing the likelihood that it will be cognitively cued by a junior user’s mark.

In an Eveready survey, a respondent is first shown an exemplar, photograph, or advertisement of defendant’s branded (or “trade dressed”) product; then, the respondent is asked an open-ended “source confusion” question: “Who makes or puts out ?” That question is followed by: “Why do you say that?” Questions as to “sponsorship confusion” and “affiliation confusion,” often in closed-ended form, typically follow, e.g.:

  • Do you believe that whoever makes or puts out :
  • ONE, is sponsored or approved by another company;
  • TWO, is not sponsored or approved by any other company; or
  • THREE, you don’t know or have no opinion?
  • [If ONE] What other company? [and] Why do you say that?

The Eveready format primarily addresses three confusion factors:

  1. similarity of marks,
  2. similarity of products, and
  3. brand strength (accessibility in memory).

Strength is the key: (i) if a schema is easily accessible, it can be cued by a similar mark even where there is little or no similarity in products; and (ii) if a brand is dominant (COKE), its schema may be cued by another brand in the category (PEPSI), even where there is no similarity of marks. If, however, the senior mark is not accessible, it obviously cannot be cued irrespective of mark and product similarity: when an “open- end question [is] used [in connection with] a mark that is not particularly well-known, it needs to be understood that the . . . “top-of-mind” awareness of the brand . . . required [by the Eveready format] may significantly underestimate [the likelihood of] confusion."

Squirt Format

In 1980, in Squirtco v. Seven-Up Co.,7 the Eighth Circuit held that results from a Squirt study supported a district court finding as to the “possibility of confusion” between SQUIRT and QUIRST for non-cola soft drinks. Over time, the Squirt format has come to be used in cases where accessibility of the senior mark in memory is low to non-existent, so that it must be made externally available to respondents as part of the survey design."

In Squirtco, respondents first heard radio ads for SQUIRT and QUIRST and were then asked:

  1. “Do you think SQUIRT and QUIRST are put out by the same company or by different companies?,” followed by
  2. “What makes you think that?”
  3. In current designs, questions as to “sponsorship confusion” and “affiliation confusion” follow.

The number of Squirt variants is vast.In one, to remove a spotlight from the brands at issue, respondents are shown an array (including the senior and junior uses) and asked:

  1. "Do you think that each of these brands is from a separate company, or do you think that two or more are from the same company or are affiliated or connected [in any way]? If you don’t know, please feel free to say so."
  3. "Which two or more brands do you believe are from the same company or are affiliated or connected?
  4. Why do you say that?

Another variant, to address objections to a side-by-side or sequential display of brands not seen in such immediate proximity in the marketplace, is a “two room” study: (a) in the first room, the respondent sees a stimulus of the allegedly infringed product; (b) in the second room, the respondent sees a “line-up” of products in the same category, including the allegedly infringing product, and is asked whether any “come from the same maker or company as the product . . . I showed you [in the first room]?”

The two-room study is an attempt to replicate the marketplace process of advertising exposure to a brand or trade dress, followed by being confronted in the market with both similar and differing brands . . . . of junior and senior marks, it relies on a recent brand display (a “recency effect” in memory) to make the allegedly infringed brand accessible. A Squirt survey and variants of the Squirt format test similarity of marks, similarity of products, and market proximity. The proximity factor is critical. In an Eveready survey, given the “accessibility” of a strong mark, an unaided comparison (involving an internal search of memory) is appropriate where the respondent is likely to encounter the junior mark (and pattern match) in the natural flow of commerce. In a Squirt format, however, where the senior mark is not “accessible” in memory, an aided comparison (involving the representativeness heuristic) is appropriate where the marks exist side-by-side in the market or if one is typically encountered sufficiently soon after the other that the recent brand or stimulus exposure (the “recency effect”) places both in the consumer’s “cognitive workspace.” A Squirt survey is based on an external review of two stimuli that must be substantially proximate for the review, under “marketplace conditions,” to occur. Absent market proximity, respondents in a Squirt design are made “artificially aware” of the competing marks.

Rhonda Harper - Survey Expert Witness

Rhonda Harper is routinely retained to formulate expert surveys, conduct rebuttal critiques, or construct rebuttal surveys to show the potential difference in results with properly designed and executed surveys. She has extensive experience and a deep understanding of survey design, sampling, question construction, data analysis, and methodological pitfalls that introduce bias or systematic error.

Located in Dallas, TX, Rhonda Harper is a former Fortune 100 C-Suite Executive in marketing, branding, consumer research, strategy, licensing, and advertising. Also a former Adjunct Marketing Professor, she has been retained by more than 95 law firms since 2005. Harper has a focus on Trademark and Trade Dress Infringement, Misleading and Deceptive Advertising, Licensing, and Commercial Reasonableness cases. She has conducted  50+ intellectual property Lanham Act surveys, produced 75+ reports, been deposed 50+ times, and served in 20+ trials and arbitrations.


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