Unified Modeling Language (UML) is the standard modeling language for object oriented system development. Despite its status as a standard, UML’s formal specification is fuzzy and its theoretical foundation is weak. Semiotics, the study of signs, provides us good theoretical foundation for UML research as UML graphical notations are some kinds of signs. In this research, we use semiotics to study the graphical notations in UML. We hypothesized that using iconic signs as UML graphical notations leads to more accurate representation and arouses fewer connotations than using symbolic signs. Since symbolic signs involve more learning efforts, we assume that expert users of UML will perform better with symbolic signs than novice users. We created an open-ended survey to test these hypotheses. The qualitative analysis of the survey process can help us gain in-depth understanding of the complexity of modeling language graphical notations. In addition, the introduction of semiotics in this research helps build a solid theoretical foundation of IS modeling method research.