agrigates now activities
new section: <imsss:sequencingCollection> <sequencing> and <presentation added to <item>s in <organisation>
- activity and its immediate children - an internal node (not leaves)
- "learning acivity"
- "a meaning ful uint of instruction"
- have a discreate start and finish
- have well-defined comletion and mastery conditions
- can be nested
- exist in context of their parents if they exist
- an effort to complete an activity
- can satisfy more than one objective.
- each attempt is completed on one activity and as part of an attempt on that activities ancesstors
- aka a sequencing session
- can be suspended (and another one attempted)
defualts defined in <imsss:sequencingCollection>
- only used if item is lacking the definition for that top level sequencing element
- Only primary one contributes to rollup
- related to list of objectives through objective map (each objective in the map has read / write flags)
- each activity has a primary objective and a set of local objectives. a local objective becomes a global objective if it is referenced as the target objective in an objective map.