- the big picture -- what is proj 1 all about?
  - helpful to map it to a more real-world experience
    - humans are better at thinking about interactions w/ &
      relationships to other humans/the real world, than they are
      thinking about abstract stuff (web pages, classes, sets, etc.)
    - Design principle #1: principle of mimesis: try to structure
      software so as to reflect/correspond to the domain that you're
      modeling.  (This is what object orientation was designed to
      support in the first place.)
    - in this case: think about a real-world scenario that mirrors the
      task at hand, then build objects to reflect that
  - example task: buying specialty items from a collectables store
    - store offers all sorts of collectables -- model trains, dolls,
      baseball cards, old music, etc.
    - customer wants to buy an original copy of the 1965 British release of
      the Beatles LP "Help".
    - goes to store front and makes the request to the salesperson
    - salesperson goes back to warehouse to see if they have that in
      stock
    - asks warehouse clerk for "Beatles AND LP AND Help AND Britain
      AND 1965"
    - warehouse clerk looks up
      - all bins marked "Beatles"
      - all bins marked "LP"
      - all bins marked "Help"
      - all bins marked "Britain"
      - all bins marked "1965"
    - takes the intersection of all of those bins to find the one that
      is the target
    - looks in that bin and finds, say, 5 items
    - reports back to sales clerk: "we have these 5 items matching
      your description"
    - sales clerk returns to customer: "we have these 5 items, and
      here's the order in which I suggest you examine them"
  - this gives us a view of two of the parts of the task: the UI
    (store front/salesperson) and the WEB DATABASE (warehouse/clerk).
  - more importantly, gives you a view of what the _interactions_
    between these two modules are
    - in OO programming, you more-or-less think of an object as a
      "noun" and a method as a "verb"
    - when designing, think about what the nouns are in the problem
      ==> objects/classes, and what the verbs/actions are ==> methods
  - these interactions can be mapped almost directly into method calls
  - ** sequence diagram **
  - illustrates the role of the Map in all of this
    - allows rapid "get" queries: words -> URLMap
  - so...  Why do we want to use the java.util.Map version of a map?