- last post: 01.01.0001 12:00 AM PDT
Cortana is a computer AI. She knows what she has access to (and then some depending on what she puts to her memory software). The only time she would have learned of the ark would be in HaloCE where she went into the control centers main computer. Even then, she may not have had the chance to learn of the Ark because the information was not present to her (due to the circumstances that were not present until the removel of the icon at the end of Halo 2).
Through my logic, it makes sense that Cortana does not know of the Ark because, at the end of Halo 2 she was not in Halo's computer system, she was in High Chairty's. And the times that she was inside Halo's computer system the information may not have been accessable to to circumstnaces at the present time. Which explains why she doesn't tell the Chief because, since a lot of the information she recieved wasn't stored in memory files, once she left the system, whatever didn't come with her she completely forgot that it was even there.
Cortana is, in a sense, a computer and her memory storage and realizations work as such.
EDIT: Cortana was able to understand the information that she did recieve because if you remember, she had said in HaloCE that she was recieving, "information, so much, so fast!" when she accessed Halo's computer (and she was also able to easily use the system to locate Captain Keyes). From this, you can "imply" that she understood the information she was given.
[Edited on 5/15/2006]