The concept of secondary meaning is straightforward in intellectual property matters. A secondary meaning survey typically seeks to assess whether a “significant” or “substantial part” of the customer class associates a trademark or trade dress with a single source.
Secondary meaning exists if respondents associate the trademark or trade dress with only one company. Although not required (a.k.a "anonymous source rule), secondary meaning surveys may ask the third question (“what company”) as a way to identify whether the trademark or trade dress is typically associated with the plaintiff or the defendant.
The measurements from these questions can be compared against standard sources or past precedents, to evaluate whether or not secondary meaning is present in sufficient quantity as to be considered substantial or relevant.