How does a two-way test differ from a one-way test in double patenting analysis?

In double patenting analysis, the one-way test and two-way test are used to determine if claims in different applications or patents are patentably distinct:

  • One-way test: The examiner compares the claims of the application under examination to the claims of the other application/patent.
  • Two-way test: The examiner performs the one-way test and then reverses the analysis, comparing the claims of the other application/patent to the claims under examination.

According to MPEP 804.02, “If a “two-way” test is to be applied, […] the examiner must determine if (i) the first-filed application claims are anticipated by, or obvious in view of, the claims of the second-filed application and (ii) the claims of the second-filed application are anticipated by, or obvious in view of, the claims of the first-filed application.”

The two-way test is generally used when the applications have different effective filing dates and were filed by the same inventive entity.

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Tags: double patenting analysis, one-way test, patentably distinct claims, two-way test