Compound component group

A compound component group contains two or more component groups that need to be grouped.

Adding a component group

You can add component groups by clicking on New group and selecting from one of three types:

• Blended: blended component group contains two or more component groups that need to be blended. Groups may contain different types of items (e.g. image and text).
• Counterbalanced: counterbalanced component group contains multiple component groups that need to be counterbalanced.
• Discrete: discrete component group contains a list of stimulus items and come in the following types:
  • Text: text component group contains a list of text items.
  • Image: image component group contains a list of images.
  • Audio: audio component group contains a list of audio items.
  • Video: video component group contains a list of video items.

WARNING: Adding a component group to an existing group will remove:

• all stimulus components derived from the component groups to which you are adding to, on any trials timeline they've been added to.
• any trials rules related to removed stimulus components.
• any trials rules related to the removed component groups.

Removing a component group

A component group can be removed by selecting it using the checkbox and clicking Delete in the toolbar above the table. You can also select and delete multiple component groups at once.

WARNING: Removing a component group will also remove:

• all sub-groups of the selected component groups. If you wish keep any sub-groups, you can drag them to another part of the stimulus set tree.
• all stimulus components derived from the component groups on any trials timeline they've been added to.
• any trials rules related to the root component group (if any) containing the group.
• any trials rules related to removed stimulus components.
• any trials rules related to the removed component groups.

Reordering component groups

Component groups can be reordered within their containing group by drag and drop.

Reparenting a component group

A component group can be moved to another group within the stimulus set tree by drag and drop.

WARNING: Reparenting a component group will also remove:

• all stimulus components derived from the both the old and new component groups (old parent and new parent) on any trials timeline they've been added to.
• any trials rules related to the root component group (if any) containing the group.
• any trials rules related to removed stimulus components.
• any trials rules related to the removed component groups.

Setting composition strategy

Click Composition: sequential to set the composition strategy for compounding the items from each group.

• Sequential: items will be selected from each group sequentially. This means that the first item will be chosen from the first group then the first item will be chosen from the second group, etc. For example, given groups A,B,C, the first compound item will be A1 and B1 and C1, the second item will be A2 and B2 and C2 and so forth.
• Random: items will be selected from each group randomly. For example, given groups A,B,C, each compound item will be composed of any item in A and any item in B and any item in C.
• Random: recompose: items will be selected from each group randomly. For example, given groups A,B,C, each compound item will be composed of any item in A and any item in B and any item in C. Items will be recomposed randomly for each set of trails that allocate this stimulus set.

Customize stimulus set (only available for compound components)

Stimulus sets containing compound components can be customized for a single trial set. Partial re-composition of compound stimulus sets allows you to recompose a subset of compound items isolated to this trial set only.

Click Stimulus set: nil and click Customize... (Figure 1).

The customize screen (Figure 2) provides the following options:

• Component: the component to partially recompose
• Number of stimuli to recompose: the number of stimuli to recompose from the component
• Force new compositions?: Forces new compositions; preventing any previous compositions being randomly generated. This type of forcing will always produce unique and previously unseen compositions (thus new compound stimuli) and therefore is not purely random

This kind of re-composition strategy might be handy when using the same stimulus set for practice and test. For example, a paired associate task where you're testing participants on their ability to recognize seen/unseen associations.