  We consider an information updating system where a source produces updates as
requested by a transmitter. The transmitter further processes these updates in
order to generate $partial$ $updates$, which have smaller information compared
to the original updates, to be sent to a receiver. We study the problem of
generating partial updates, and finding their corresponding real-valued
codeword lengths, in order to minimize the average age experienced by the
receiver, while maintaining a desired level of mutual information between the
original and partial updates. This problem is NP hard. We relax the problem and
develop an alternating minimization based iterative algorithm that generates a
pmf for the partial updates, and the corresponding age-optimal real-valued
codeword length for each update. We observe that there is a tradeoff between
the attained average age and the mutual information between the original and
partial updates.
