Parties often offer expert declarations during the claim construction process.
These declarations can be of varying utility. Sometimes, parties offer a detailed and helpful explanation of how the technology works. Other times, parties offer a useless, conclusory expert declaration that says little more than "a person of ordinary skill in the art would understand the term to mean [whatever construction the attorneys who hired me proposed]."
But, while declarations are common, in my experience live testimony from experts during a Markman hearing is pretty rare in D. Del. That's why I thought it was worth noting that, this week, Judge Burke granted an opposed request to permit …