It doesn't generate random results, it links the answers to the results in a fairly simple way. If you answer mostly option 1, you'll get result 1. A nice touch is that the answer options are randomized in the front end, so the user gets a different sequence.
I suppose the result is random if your answers balance out among the different options. There is also no possibility to calculate a more complex/nuanced result.
Say, I make a personality test to find out if you're a tiger, lion or lama. If 40% of your answers are 'lama' answers, 25% are 'tiger' answers and another 35% are 'lion' answers, the result should logically be that you're a lion, since the tiger answers point towards a feline character. Yet, with this plugin, you'd be a lama.
But, then again, maybe I'm taking this kind of test too seriously :-)