Currently, pairings are based on where students are in the curriculum. Students will only be paired with someone who is currently in the same unit, sometimes even the same lesson as you.
If you find yourself paired with someone much further along than you, this is a great opportunity to ask questions, talk through a concept and get idea for how to approach an upcoming Lab.
If you find yourself paired with someone who is at an earlier point in the curriculum, you're in luck. You will be able to test your own understanding of a concept or previous lab by talking it through with another student. Who knows, you might also find yourself learning a new way to solve that lab.