US Patent 8175925 Position-based item identification in a materials handling facility

Positional placement guidelines for storing items in an inventory area may allow determination and tracking of the position of the items in the inventory area. Position information may be associated with each item in a materials handling facility to assist in locating an item in an inventory area. The position information may represent a position relative to the inventory area and/or to the other items therein. Position information may be determined based on a count of items in the inventory area or based on a time stamp corresponding to the time the item was stored in the inventory area. Position information may be presented to an agent to facilitate picking the item with or without descriptive information. Feedback may provide an indication that the position information is incorrect and may trigger a review or a reset of position information for one or more items in the inventory area.