Since information systems are pervasive in the busi-ness and non-business areas, the issue of extending researches on information systems to knowledge sys-tems and e-business systems is one of the most profit-able topics of researches. We propose a historical, discontinuous changes introducing ambiguity in explaining and interpreting innovative nature of three paradigms of systems: information systems, knowledge systems, and e-business systems. Resorting to the historical perspective in developing ideas into meaningful themes, we proposed a discrete continuity in interpreting changes of paradigms of sys-tems. Discrete continuity may be explained by ambigu-ously-shared meaningful perspectives applied to differ-ent paradigms of systems and interpretive elements of each system. The discrete continuity has been adopted to make ambiguity utilized may have instrumental contribution in researches. The engrafted ambiguity in systems design, development, and use could have enduring instrumental value in interpreting the types or variants of systems in each paradigm of systems.