At the Trademark Trial and Appeal Board, just two of the 13 DuPont factors for likelihood of confusion can determine the outcome of over 99 percent of cases, according to new research by Southern Illinois University Assistant Professor Thomas Reichert. He tells MLex that this “multifactor collapse” should lead to a simplification of the legal doctrine.
The 13-factor DuPont analysis to determine likelihood of confusion is not as complex as it appears when practicing before the Trademark Trial and Appeal Board, according to new research. Just two of the factors — the first and second — can be used to predict whether the board finds challenged marks confusing 99.57 percent of the time, Southern Illinois University Assistant Professor Thomas Reichert found.
Thomas Reichert
Factor one covers the disputed marks’ similarity in appearance, sound or connotation, and factor two covers the similarity in nature of the goods themselves.
Reichert’s paper, “Doctrine, Data, and the Death of DuPont,” published last month, argues that the DuPont factors aren’t a comprehensive analysis at the TTAB, and have instead become a box-checking exercise.
“If one and two are satisfied, the rest is mere recital,” Reichert tells MLex.
Reichert’s work builds off a 2006 study by Yeshiva University Professor Barton Beebe that found the first two factors determine trademark likelihood of confusion findings in most district court opinions from 2000 to 2004, by going through each decision by hand. Reichert expanded the research to look at 4,000 TTAB opinions from 2000 to 2025.
Using an AI model, Reichert was able to determine whether each of the 13 factors was addressed by the TTAB panel and whether each factor weighed in favor, against or was neutral as to confusion. By analyzing word choice in opinions, Reichert also determined how much each factor weighed in either direction, for or against likely confusion.
Reichert said the result was surprising: If both factors one and two weighed in favor of confusion, the board found confusion likely over 99 percent of the time. Either of the two factors weighing against confusion led to an overall finding of no likely confusion at about the same rate.
“When I started looking at the first sets of cases coming back, and I was just like, ‘Okay, what's wrong?’” he said. “Data from the natural world typically doesn't look this clean, but data from humans applying heuristics and modeling to their own workflows can.”
While just the first two factors can predict the outcome in 99.37 percent of cases, adding the remaining factors predicts 99.79 percent of cases, an insubstantial increase with the remainder being outlier opinions.
Reichert said his research shows that to TTAB panels, the DuPont analysis is more a threshold test of the first two factors alone, instead of a comprehensive 13-part analysis.
He linked the findings to a theory of “multifactor collapse,” that judges commonly rely on only a small part of large multifactor tests in legal analysis, with much of the tests only serving a rhetorical purpose. Research from other academics has shown an overemphasis on transformativeness, the first of four fair use factors in US copyright law, in qualified immunity law and with determinations of personal jurisdiction, among others.
With the DuPont factors, the failure to utilize the entire test by the TTAB harms practitioners and clients, Reichert argued, resulting in additional litigation costs spent fighting over factors that don’t matter and less predictable case outcomes.
A solution could be the implementation of a new categorical, burden-shifting rule to simplify TTAB practice, he proposed. If an opposer can prove that the first two factors favor confusion, the burden should shift to the trademark owner to show how the remaining factors weigh against a finding of confusion.
“Simplification of practice is going to have to come from the top down. I think that would end up making a cleaner signal to practitioners, to business owners, applicants, registrants, to the courts, to everybody involved in this of exactly what the step-by-step process is,” Reichert said. “Because right now ... it's still at the start of every single one of these cases. We say, ‘It's a 13-factor, multifactor test, no single factor controls.’ We still have that recital, and it's a recital that's been going on for 50 years, and the data seems to indicate it's just that.”
“The information transparency that we give to the public should be how it actually operates in practice, not how we want it to operate in theory,” he added.
Such burden-shifting may not be difficult to implement at the TTAB, with the right political will behind it. US Patent and Trademark Office leadership has substantially changed practice at the Patent Trial and Appeal Board in the last year, but has largely left trademark practice alone. In theory, the office could similarly weigh in on the application of the DuPont factors.
Reichert plans to continue his research to focus on district court and appellate court decisions, though differences in how each circuit applies likelihood of confusion tests complicate data collection and processing. It’s also unclear if the reliance on factors one and two is as strong in other venues.
“It's important to draw a distinguishing line between the TTAB and actual litigation in the federal courts, understanding that at the registration stage, oftentimes we aren't going to be able to collect a lot of the other evidence that is indicative of the other factors,” Reichert said.
“There are still outlier cases, so this isn't a complete dismissal of the other 11 factors. This is simply illuminating how the TTAB has been operating,” he continued. “We can inform practitioners that in 99.5 percent of your cases, almost every case that you'll touch upon, you should be spending the overwhelming majority of your time and efforts and considerations towards those first two factors.”
Please email editors@mlex.com to contact the editorial staff regarding this story, or to submit the names of lawyers and advisers.