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Ninth Circuit

Ninth Circuit Likelihood of Confusion Factors

Ninth Circuit Likelihood of Confusion Factors

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Each of the thirteen federal courts of appeal have their own test for evaluating whether a likelihood of confusion exists between two trademarks. Although the tests are not identical, most of them are substantially similar and use many of the same factors. And the factors are non-exclusive.

The Ninth Circuit includes the following jurisdictions:

  • District of Alaska
  • District of Arizona
  • Central District of California
  • Eastern District of California
  • Northern District of California
  • Southern District of California
  • District of Hawaii

The Ninth Circuit uses the Eight Sleekcraft Factors when considering likelihood of confusion cases:

  1. The strength of the mark
  2. The proximity of the goods
  3. The similarity of the marks
  4. Evidence of actual confusion
  5. The marketing channels used
  6. The type of goods and the degree of care likely to be exercised by the purchaser
  7. The defendant’s intent in selecting the mark
  8. The likelihood of expansion of the product lines

AMF Inc. v. Sleekcraft Boats, 599 F.2d 341, 348-49 (9th Cir.1979).


In the Ninth Circuit, trademark survey expert Ms. Harper has been retained for 27 cases.

Rhonda Harper Expert WitnessMs. Harper has been retained for cases filed in the:

  • Northern District of California
  • Southern District of California
  • California Central District
  • Superior Court of the State of California for the County of Los Angeles, Central District
  • Central District of California, Central Division
  • Superior Court of California County of San Diego
  • Central District of California Eastern Division Riverside
  • Eastern District of California
  • Nevada Southern Division
  • Western District of Washington at Seattle
  • Superior Court of the State of Arizona in and for the County of Maricopa
  • Northern District of California, Jose Division
  • Northern District of California, San Francisco Division

Retained by more than 120 law firms, Ms. Rhonda Harper is courtroom proven in virtually every circuit along with JAMS and TTAB.  Ms. Harper's 30 year career includes serving as a Fortune 100 chief marketing officer and an adjunct marketing professor. In addition to providing litigation consulting and research in the areas of business, licensing, marketing, advertising, and strategy, Ms. 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 the methodological pitfalls that can introduce bias or systematic error.

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