1. A method of enhancing the quality of data stored in a system, the method comprising: receiving data from a first data enterer; accepting data received from the first data enterer into the system if the data are entered in a format compliant with a first set of rules; receiving first additional data from a second data enterer, the first additional data being related to the data received from the first data enterer; and accepting first additional data received from the second data enterer into the system if the data are entered in a format compliant with a second set of rules.