This document discusses measuring the quality of archived webpages or "mementos" when some embedded resources like images or CSS are missing. It found that a "damage rating" approach, which considers factors like the size, position and importance of missing resources, was a better indicator of memento quality than just the percentage of missing resources. A study with Amazon Mechanical Turk users found they agreed more with damage ratings than percentage missing when comparing mementos. The quality of mementos in the Internet Archive was also found to generally improve over time despite more resources being missing.