Beginning C# 2008 Objects: From Concept to Code

10.7. Information "Flows" Along the Association "Pipeline"

Beginning modelers also tend to make the mistake of introducing undesired redundancy when it comes to fields in general. In the association portrayed in Figure 10-32, we see that the name field of the Professor class is inappropriately mirrored by the chairmanName field of the Department class.

Figure 10.32. The name and chairmanName fields are redundant.

Although it's true that a Department object needs to know the name of the Professor object that chairs that Department, it's inappropriate to explicitly create a chairmanName field to hold this information. Because the Department