I believe that an integral part of the course is for you to think about applications of the material to real-world contexts. That is, why many of the essay prompts ask you to do exactly that.
It also means, however, that assessing the essays on an objective basis is difficult. I would therefore like to give you a bit more of a guidance.
What I am looking for are two things: analytical rigor and creativity.
I define analytical rigor as the ability to apply materials from class or elsewhere (feel free to include any relevant knowledge that you may have about a field/topic) to the problem at hand. This implies that the concepts and ideas have direct relevance to the problem and its solution and are used in a consistent way.
I define creativity as the ability to come up with novel ideas and solutions that go beyond what we have done in class. For instance, talking about a concept in class for domain X and using it for domain Y would still be a demonstration of analytical rigor (knowledge transfer), but it would not be very creative.