Field Notes

As you learn patterns, it is useful to look for the following forces and concepts:

• What implementations does this pattern hide? Thereby allowing me to change them.

• What commonalities are present in this pattern? This helps me identify them.

• What are the responsibilities of the objects in this pattern? As it may be easier to do my decomposition by responsibility.

• What are the relationships between these objects? This will give me information about the forces present with these objects.

• How may the pattern itself be a microcosmic example of designing by context? This affords me a better understanding of why the pattern is good design.