Data transfer over a computer network relating to a data object of a multiple user network application, from a network user who owns the data object to an updating user, is achieved by transfer of a subset of data fields that define the data object, such that the subset of data fields is specified by the updating user and is less than a full update transfer comprising updated values for all the data fields that define the data object. Each data object is defined by multiple data fields, such that the transfer of a subset of the data object data fields ensures that the network bandwidth utilized for data updates will be reduced from the situation in which all the defining data fields for an object being updated are transferred over the network.