The ability to convince an audience is the main factor that determines the effectiveness of communication. According to Moriarty (1997), seeing promotes believing. This indicates that people tend to believe what they see than what they hear. I also found out that people would tend to remember more of what they saw than what they heard. Charts and graphs transform complex information into a form that an ordinary person can comprehend (Moriarty, 1997). It is also notable that most people are not conversant with numbers and figures. A graphical representation of a numerical figure or a chart representing a certain fraction or a percentage will have a greater impact on the audience than actual numbers or figures. In such cases, the effectiveness of the communication will depend on the ability of the audience to interpreter different information presented in a chart or a graph. The complexity of a chart or a graph determines the ability of the audience to grasp the intended message. I also realized that the complexity of a graph or a chart depends on the size of various components in relation to their intended representation.