Representation is a key concept for information systems (IS). IS is designated to provide information. However, the most available information systems such as databases using a computer are actually data storage and management systems because all they handle are data, which may be used to represent information. Therefore, a good understanding on the relationships between data, information and representation is vital for our study of information systems. And yet, it would seem that in the literature of information systems, the notion of representation has not been well studied, and in particular, how a possible representational relationship between two sets of data constructs may be systematically identified and how this representational relation may be explored for bearing on IS problems would seem worth looking at. The results of our investigation show that representation is a special type of signs created or being used by human agents to carry information about other states of affairs. Any representational relationship is realized and underpinned by information flow between components within an information channel. Moreover, representation can be quantitatively measured as long as certain conditions are met. The information content of representation reveals what you could possibly learn from it and the semantic content of representation is the proposition that a human originator intended to convey by using the representation. In addition, schema connections (i.e., connections between elements within a data schema) can be identified by examining the representational relationship between data entities.