A pathway can make students work through its lessons in order, or let them pick their own route.
Switching between them
Open the pathway from My Library and go to the Settings tab. Under Lesson Access, choose:
Sequential (must complete in order). A student has to finish one lesson before the next unlocks.
Flexible (any order). Every lesson is open from the start.
Click Save. Sequential suits a unit that builds on itself; flexible suits a revision bank where students dip into whatever they are weakest at.