In 1961, in Polaroid Corp. v. Polarad Electronics Corp., Judge Friendly articulated eight “variables” to be weighed in assessing likelihood of confusion between marks used on noncompeting goods. Utilization of these variables (and close variants) quickly spread to competitive goods cases, other circuits, and the Trademark Office. The variables today remain substantially intact; confusion factor analysis, indeed, occupies three sections of the Restatement (Third) of the Law of Unfair Competition.
In terms of a consumer’s mental processing, the four principal marketplace factors, analyzed in virtually every case, are:
1. similarity of marks;
2. similarity of products;
3. strength of the senior mark; and
4. market proximity of the respective goods or services.
The Restatement (echoing the courts) warns that the factors are not a “mechanistic formula,” are not all applicable in every case, and vary in relative importance depending on the facts of a particular case. Nonetheless, courts typically grind mechanically through all the variables, and the winner, more often than not, is the party that accumulates the most factors, with ties being resolved against the party with the burden of proof.
Each factor has elsewhere been individually and ehaustively
analyzed, and it is not my purpose to review or summarize the case law or the literature as to any variable. Now, however, that the trademark bar has had fifty years of experience with Polaroid and its progeny, it is appropriate to rank at least the principal factors and, more particularly, to relate them to how confusion occurs. It is time to understand how the variables work in consumers’ minds and in the marketplace to produce or preclude a likelihood of confusion.