Likelihood of confusion surveys are basic in any trademark litigation. Sometimes they’re the only way to actually prove likelihood of confusion.

There are two main formats that are widely accepted, the Eveready format and the Squirt format, each with key differences.


Eveready survey

The Eveready format, as its name implies, was first used in Union Carbide Corp. v. Ever-Ready, Inc. It asks the survey respondents a series of questions to determine whether they associate one brand’s products or services with the other. There is no side-by-side comparison since that could detract from the strength of the results. It’s a widely accepted test, with some districts finding confusion with as little as 15-20 percent of positive results.

In this format, the respondent is shown an example of the defendant’s branded product and asked an open-ended “source confusion” question, such as: “Who do you think makes this product?” and “Does any other company sponsor or approve this product?” Follow up questions ask respondents to explain their rationale.

The Eveready format is made to address three confusion factors:

  1. Brand strength

  2. Product similarity

  3. Brand similarity

When to use the Eveready survey: Given its nature it’s mostly effective when used in cases involving popular brands, since those brands are usually already remembered by the audience.

Squirt survey

likelihood of confusion - online survey image

Also referred to as “the Lineup format”, the purpose of this format is to use side-by-side comparisons to measure the level of confusion. It was first used in Squirtco v. Seven-Up Co, where the respondents were shown two radio ads by the rival companies Squirt and Quirst, then asked if they believed the ads represented the same company. However, not all surveys have to be done in this exact way.

There are a lot of variants to the Squirt test, depending on the need of the survey. In one of them, the survey first presents the defendant’s product by itself and then a lineup of similar products including the allegedly infringed product. Then the respondent is asked if they think any of the products shown in the lineup come from the same company than the first one.

When to use the Squirt survey: The purpose of this test is to replicate marketplace conditions. Therefore it’s mostly used when the brands aren’t famous or easily recognizable, as it relies on the “proximity factor”.