Drafting the expert declaration is another critical task for Patent Owners during the inter partes review ("IPR") discovery period. As noted in our previous post, IPR expert witnesses provide declarations as affirmative testimony in lieu of live testimony before the Board at the hearing. Because the expert witness will not be able to provide live testimony before the Board, expert declarations are the final evidence of the experts' opinions, as there is no opportunity to correct misstatements or mistakes. Due to the procedural schedule of the IPR system, Patent Owners have the unique opportunity to file their expert declarations after deposing Petitioners' experts, providing a