Overview

An attempt on an activity always occurs within the context of an attempt on its ancestors. If you are reading a sentence in a book, you are also:

  • Reading a paragraph
  • Reading a page
  • Reading a chapter
  • Reading the book

As a learner progresses through a series of content objects, those content objects may report status; therefore, the status of the parent activity is dependent on the status of its children activities.

Rollup

Rollup is the process of determining a cluster activity’s status information based on its children’s status information. Learners do not directly interact with a cluster; therefore, rollup is the only mechanism for the status of a cluster to be determined. The image below shows that Activity A’s status information is rolled up from its children, Activity 1, Activity 2 and Activity 3. The status shown for Activity A is the “after rollup” status. It is the status that resulted from Measure Rollup.

Rollup Measure

Measure (score) always rolls up, if it exists (is not “unknown”) for any child. Content Developers can ‘turn off’ a measure, at any level, by setting its weight to zero. By default, measure does not affect satisfaction status; however, a Minimum Objective Measure may be applied.

If a Minimum Objective Measure is applied, the activity’s measure will be evaluated against a threshold to determine the activity’s satisfaction status.

Rolling Incomplete Information

In some cases, rollup will not be able to determine an activity’s status if some child activity has an “unknown” status. Also, by default, Suspended activities DO contribute to rollup, which is not always the desired result — this can result in premature success and failure.

Conclusion

In general, rollup is used to provide a form of feedback about the learner’s experience through an activity by looking at the sum of an activity’s parts. Therefore, the idea of rollup is to simply sum up the parts of a cluster.