9. An apparatus that can be used to specify a subset of data, comprising: a communication interface; a storage device; and one or more processors in communication with the storage device and the communication interface, the one or more processors implement a user interface using the communication interface, the one or more processors receive a first input at the user interface for a first field of a natural language expression, the first input indicates a first data value for the first field, the one or more processors access options for a second field of the natural language expression that are determined based on the first data value and data stored in data group, the one or more processors display the second field and the options for the second field, the one or more processors receive a second input at the user interface for the second field of the natural language expression, the second input indicates a second data value for the second field from the options for the second field, the one or more processors access options for a third field of the natural language expression that are determined based on the second data value and data stored in the data group, the one or more processors display the third field and the options for the third field, the one or more processors receive a third input at the user interface for the third field of the natural language expression, the third input indicates a third data value for the third field, the second data value indicates a relationship between the first data value and the third data value that exists in the data group, a result of receiving the third input is an updated version of the natural language expression that includes the first data value, the second data value and the third data value as natural language, the one or more processors access and report a subset of the data group that corresponds to the natural language expression that includes the first data value, the second data value and the third data value as natural language.
9. An apparatus that can be used to specify a subset of data, comprising: a communication interface; a storage device; and one or more processors in communication with the storage device and the communication interface, the one or more processors implement a user interface using the communication interface, the one or more processors receive a first input at the user interface for a first field of a natural language expression, the first input indicates a first data value for the first field, the one or more processors access options for a second field of the natural language expression that are determined based on the first data value and data stored in data group, the one or more processors display the second field and the options for the second field, the one or more processors receive a second input at the user interface for the second field of the natural language expression, the second input indicates a second data value for the second field from the options for the second field, the one or more processors access options for a third field of the natural language expression that are determined based on the second data value and data stored in the data group, the one or more processors display the third field and the options for the third field, the one or more processors receive a third input at the user interface for the third field of the natural language expression, the third input indicates a third data value for the third field, the second data value indicates a relationship between the first data value and the third data value that exists in the data group, a result of receiving the third input is an updated version of the natural language expression that includes the first data value, the second data value and the third data value as natural language, the one or more processors access and report a subset of the data group that corresponds to the natural language expression that includes the first data value, the second data value and the third data value as natural language. 17. The apparatus of claim 9 , wherein: the communication interface includes display and a keypad.