When building your scenario it is possible to build it "Facilitated" or "Self-Paced".
With this option, there will be a moderator running the experience from his or her own dashboard. It's the injects in the facilitator dashboard that determine when content is published to the players.
There isn't a facilitator sending injects or moderating the excercise - this means each player proceeds at their own pace with th exercise advancing based on decisions they make.
To change this go to your scenario configuration (Scenario > Configure...) or to your Default Settings (Click on the gear icon at the top).