uncertainty vagueness Jinjing Guo classification to be confirmed GEORGE J. KLIR (1989) IS THERE MORE TO UNCERTAINTY THAN SOME PROBABILITY THEORISTS MIGHT HAVE US BELIEVE?*, International Journal Of General System, 15:4, 347-378, DOI: 10.1080/03081078908935057. vagueness is associated with the lack of precise or sharp distinctions or boundaries Oliver He Jie Zheng cloudiness fuzziness haziness imprecision indefiniteness indistinctiveness sharplessness unclearness 模糊