How to present 90% of stimuli and 10% of another set of stimuli

I would like to create an experiment where the participant will see a set of stimuli 90% of the time throughout the experiment and the last 10% another set of stimuli. How do I do this?

Thank you.

I would like to clarify. You would like 90% of the stimuli presented throughout the experiment. Then, sometime later in the experiment have the last 10% be presented to the participant?

Essentially yes but I would like the 2 stimuli sets be presented randomly through out the experiment.

I see on another thread you were looking to upgrade to SuperLab 5. There are two demo experiments attached to demonstrate two different ways this is done in SuperLab 5. Both experiments show how to randomly choose 45 out of 50 items for one block, then use the remaining 5 items in another block (or blocks).

The first experiment is named “divide list in two using times this trial was presented.” It uses an action within “Block 1” under the Extra Actions tab.

  • Present a maximum of "45" trials
Then under the trial named "list-randomization is enabled here," there is one more action under the [B]When to Present[/B] tab.
  • Present trial only if the following criteria are met: "Number of times this trial has bee presented =0"

The second experiment is if you need to repeat the two subsets several times. This demo experiment is named “divide list in two using tags and rules.” It uses a Counter Parameter, Tag Sets, Rules under the Block level, and Rules under the Trial Level.

  • Under Block 1 randomly chooses 45 of the 50, and tags them as "90-percent" subset members. You can see how these actions were created within the Extra Actions and Rules tabs
  • Block 2 presents the remaining "10-percent" subset (the remaining 5 out of 50 items)
  • Block 3 presents the same 45 items as block 1, but in a newly-shuffled sequence
  • Block 4 presents the same 5 items as block 2, but in a newly-shuffled sequence
  • Block 5 presents the same 45 items as blocks 1 and 3, but in a newly-shuffled sequence

divide list in two using times this trial was presented.sl5 (6.25 KB)

divide list in two using tags and rules.sl5 (11.8 KB)