Abstract: An online concierge system compensates pickers who fulfill orders including one or more items based in part on weights of the items included in an order. Because the online concierge system does not physically possess the items that are obtained, the online concierge system cannot directly weigh the items and weights specified for items in a catalog from a retailer may be inaccurate. To more accurately determine weights of items, the online concierge system trains a weight prediction model to estimate an item's weight from attributes of the item and uses the output of the weight prediction model to determine compensation to a picker. The weight prediction model may output a predicted weight of an item or a classification of the item as heavy or light. Where discrepancies are found between a predicted weight and the catalog weight of an item, additional information about the item is obtained.

Abstract: A method for optimizing order fulfillment in a warehouse by an online system. The system receives an item catalog from an inventory system, which includes item locations. The system also obtains a taxonomy that organizes items into hierarchical levels based on attributes. When an order is placed by a user, the system checks whether the item catalog contains location data for each item. If an item's location is missing, the system identifies alternative items from the taxonomy with shared attributes and uses the location of a selected alternative item as a proxy. The system determines a picking sequence for the items in the order, optimized to minimize travel distance within the warehouse, and transmits the sequence to a shopper's device for fulfillment.

Abstract: An online concierge system receives information from a warehouse including locations of items within the warehouse. When a shopper selects an order for fulfillment from the warehouse, the online concierge system sorts the items for the shopper to minimize the time spent in the warehouse using the received information. When the online concierge system does not receive a location of an item within the warehouse, the online concierge system obtains a taxonomy for the warehouse including multiple levels, with each level having a different level of specificity. The online concierge system determines a higher level in the taxonomy for the item and identifies other items offered by the warehouse having the determined category. The online concierge system infers a location of the item within the warehouse used for sorting items of the order from locations of the other items within the warehouse and times when shoppers retrieved the other items.