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A set of tracking status information is associated with each attempt on each activity as defined by the tracking model (refer to Section 4.2). Each leaf activity in the activity tree tracks a learner’s interactions with the activity’s associated content object. SCOs may communicate status information, which is used to affect the activity’s tracking status information. Assets do not communicate status information. Sequencing information can be applied to activities associated with such content objects using either Objective Set by Content set to False or Completion Set by Content set to False; in these cases, the LMS’s sequencing implementation will directly set the corresponding activity’s tracking status information.
Cluster activities can not provide content objects and have no way to directly set their status information. The status of a cluster activity is based on the status of its children; the process of evaluating a cluster’s status information is called “rollup.” Figure 4.6a shows a cluster with three children; this figure will be used throughout this section to illustrate the various rollup processes. The status information of the cluster activity (A) is determined, through rollup, from the status information of the cluster’s children (1, 2 and 3).
Figure 4.6a: Activity Status Information Used During Rollup
The term “Rollup” is used throughout this section to mean: “The process of determining a cluster activity’s status information based on its children’s status information” – this phrase is synonymous with “Apply the Overall Rollup Process.”