Measuring grey characteristics of association grey knowledge

Association grey knowledge (in brief spoken of as grey knowledge) is introduced. By making use of difference information entropy, the grey degree which measures the grey characteristics of grey knowledge is given. Some theorems and propositions related to the grey degree and grey characteristics of grey knowledge are obtained. The bigger (or smaller) is the grey degree of grey knowledge, the greater (or lesser) is its grey characteristics, vice versa. It is pointed out that grey knowledge may extend or be transmuted white knowledge.