12. A method as claimed in claim 1 , wherein the measure of language content used in the message is a measure of the tone of the language used in the message.
12. A method as claimed in claim 1 , wherein the measure of language content used in the message is a measure of the tone of the language used in the message. 14. A method as claimed in claim 12 wherein the step of forming a measure of the tone of language used in the message comprises: counting a number of occurrences of each of a plurality of tonal indication words.