What factors should be considered when reviewing artist proposals?

Part of the job of commissioning public art is narrowing down proposals to the best possible candidates for the commission.  Depending on the size of the commission and agency resources, this process may be conducted over a single or multiple rounds, all with the goal of narrowing the list of candidates.  Top candidates are often asked to provide additional information, more detailed proposals, or sit for interviews.  In order to narrow down entries, some local art agencies use a ranking system (1-5, for example).  Many consider the quality of past work by the artist, the artist’s ability to create a project that fit the commissions goals, including financial planning and organization, experience with previous public art commissions (particularly those with a comparable budget and scale), and the artist’s availability, among other factors.
You may also wish to consult the evaluation criteria used for contractors or bidders for other city services.