The hypothesis for any experiment is the educated guess as to the outcome of the experiment you are about to conduct. A reaonable hypothesis for this experiment would be "Students who were administered 'Super Student' demonstrated measurable gains in time spent on task."
The independent variable in any experiment is the variable you change because you think it is the one that makes the difference in the outcome of the experiment. The dependent variable is what you observe as a result of changing the independent variable. The independent variable here would be the students who took the "Super Student" and the dependent variable would be the increased time they spent on task.
The control group is the group of students who were not adminstered the "Super Student" dietary supplement, so you can have a group of students who have all the variables "controlled". This is a group to compare the experimental group to.
And finally, randomization means selecting the students in a random manner, so the outcome could not be based upon an outside factor such as favoritism or categorizing. For example, selecting every 3rd student, every 4th student, so as to select a random sampling of the student population available.