Observer pattern

PART A DUE: 11:59PM, Friday, November 20, 2015

PART B DUE: 11:59PM, Sunday, November 22, 2015

10 points

Goal: This Discussion Assignment asks you to practice concepts related to the Observer pattern.

Problem Statement:

The Observer pattern described in the Larman text and the notes specifies how to separate Observer objects from Subject objects. The pattern does not precisely state whether a ConcreteSubject or ConcreteObserver or something else should invoke the notify() operation.


  • Answer the question: Who should invoke notify() and when? Or perhaps you think that the Observer pattern should not be used at all. Justify your answer and and provide options.
  • See if your discussion group can reach a consensus on this issue.

Discuss this with the other members of your topic forum.

Part A (5 points)

Part A consists of your initial suggestions posted to the private discussion group "D9".
This must be more than "Me, too!" or "Sounds good!"

Be sure to clearly state the reasons or rationale behind your suggestions
If you have access to facts or other opinions that support your opinion, cite those references

Part B (2 + 3 = 5 points)

In the private discussion group "D9", post a response to the initial postings. (2 points)
In the private discussion group "D9" prepare a final group posting that includes a consensus answer, if a consensus is reached. You may describe areas where you are in agreement and those where you are not.

Make a final posting in the public discussion group called "Final group posting: Discussion Assignment 9". Indicate your group name in the thread title. (3 points)

If you include quotation or thoughts from other sources, be sure to cite them appropriately (author, title, publisher, page, etc.).
You may use HTML within these messages.