Scenario: You own a software development company that has been hired to build an online classified ads website (refer to Craigslist.com as an example).

Object Modeling

1. Identify all of the different human actors you can think of. Starting with Humans as your Superclasses, create a diagram that organizes the actors into Classes and Subclasses (again using the diagrams in Chapter 6 as an example). Include two attributes with each object (Superclasses, Classes, and Subclasses) to demonstrate parent/child inheritance (in other words, which attribute would inherit down from a Superclass object to a Class object, and then again from a Class object to a Subclass object).
2. Create a use case description for two different actors (for a total of two use case descriptions).
3. Create a use case model for each use case description.
4. Create a use case diagram that includes all three use cases.

Data Design

5. Using a diagramming tool, create an Entity Relationship Diagram (ERD) that models the following scenarios:
   1. A user can create an account
   2. A user can list things for sale
   3. A listing can have photos
   4. A listing will automatically expire
   5. A user can view their listing history

Be sure to include relevant attributes in your tables, identify all Primary & Foreign Keys and use crows-feet annotation to demonstrate cardinality.