12. The computer readable medium of claim 11 , the operation further comprising: obtaining the reference based on a number of human assistants who have provided choices associated with a category associated with the reference.
11. A non-transient computer readable medium storing therein a program for causing a computer to execute an operation, including prioritizing items comprising: procuring a task to be performed; obtaining a reference associated with the task; selecting a group of items associated with the reference; notifying a member of the group in an order based on a ranking of the group for the reference; and adding items to the group when all members of the group have been notified and the task is incomplete.