An attribute-value system is a basic knowledge representation framework comprising a table with columns designating `` attributes '' ( also known as `` properties '' , `` predicates , '' `` features , '' `` dimensions , '' `` characteristics '' or `` independent variables '' depending on the context ) and rows designating `` objects '' ( also known as `` entities , '' `` instances , '' `` exemplars , '' `` elements '' or `` dependent variables . '' ) . An attribute-value system is a basic knowledge representation framework comprising a table with columns designating `` attributes '' ( also known as `` properties '' , `` predicates , '' `` features , '' `` dimensions , '' `` characteristics '' or `` independent variables '' depending on the context ) and rows designating `` objects '' ( also known as `` entities , '' `` instances , '' `` exemplars , '' `` elements '' or `` dependent variables '' ) .