When you choose individual assignment, each included participant will be randomly assigned a condition.
When you choose within-subjects assignment, every time a participant marks a decision point, they will receive a new condition. You can choose what kind of ordering you want for the conditions. Random will select a new random condition each time. Random Round Robin will randomly order the experiment conditions, and when it runs out of conditions, will create a new random ordering. Ordered Round Robin will deliver the same sequence of conditions over and over again.
When you choose group assignment, you then choose one of the group types defined in the . Each group will be randomly assigned a condition and each participant in a group will receive the same condition.