Lesson clusters

Clusters are special navigational sections in a Lesson. A "cluster" is a group of pages. It is formed by placing a "cluster" page at the start of the group and an "end cluster" page after the last page in the group.

Note: If you are a Moodle administrator looking for information on using multiple machines in a server cluster see the Performance page instead.

What are clusters?

The typical cluster group (or section) contains question pages and we will focus our attention on this kind of cluster.

Consider a series of question pages: Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8. This represents 8 questions in a Lesson.

A cluster is started in the logical order with a cluster page. Clusters should be completed with an End of Cluster page for best results (otherwise they treat the End of Lesson as the End of Cluster).

The teacher might put some of them in a cluster, where C1 is the first "cluster" page and EC1 is the first "end cluster" page in the lesson.

• Q1, C1, Q2, Q3, Q4, Q5, Q6, Q7, EC1, Q8.

A cluster represents a set of pages from which one or more may be randomly chosen. Questions within a cluster are randomly selected by choosing "Random Question within a Cluster" as the jump in the "Start Cluster" page. Questions within a cluster may either link to the End of Cluster to exit the cluster, or jump to any other page in the lesson. They may also jump to an unseen question within the cluster but this causes problems when the questions have all been seen if the student is allowed to re-enter the cluster in the same lesson attempt.

Note: the start and end cluster pages are not seen by the student. In the teacher's edit mode, these pages appear to have a title, page contents (with the standard toolbar) and a jump. But like an end of branch page, they are not visible to the student.

Sub-Clusters

Clusters can contain sub-clusters by using Branch Tables and End of Branches. To implement this, set up a cluster as normal with a Cluster page followed by question pages (with the jumps set up the same as above) and ended with an End of Cluster page.

• Q1, C1, Q2, Q3, Q4, Q5, Q6, Q7, EC1, Q8

To set up a sub-cluster, wrap a group of questions with a Branch Table and an End of Branch.

• Q1, C1, Q2, Q3, B1, Q4, Q5, Q6, EB1, Q7, EC1, Q8

Neither the content nor the jumps of the Branch Table and the End of Branch have importance. Rather the two pages act as markers for the sub-cluster within the main cluster. When the student attempts the lesson, only one random question page within the sub-cluster will be displayed to the student.

When to use a cluster?

A cluster in the lesson works as if you want to place a series of questions that appear in random order for each student.

In the example: Q1, Q2, C1, Q3, Q4, Q5, EC1, Q6, Q7, Q8, when the student reaches C1, the teacher might set the jump. to go to an unseen question in the cluster. When a jump in Q3, Q4 and Q5 is set to go back to C1, the student will see a "new" question in the cluster. When the student has seen all the questions in the cluster, they will be sent to EC1. The student will never see EC1, just be redirected by its jump.

Of course a jump in Q3, Q4 and Q5 could be set to Q6, thus the student would leave the cluster and pass over EC1.

Special uses

Looking for a page that redirects without the student seeing it? Alison Schubert discovered that an end of cluster will fill that function. As long as it is not placed within an existing cluster, insert it any place in a lesson. The student will not see it.