The GRE tests two sections of a student’s analytical writing skills: The Issue Task assesses how well you can develop and support your own position on an issue.
To respond to the Issue Take, you need to take a position either agreeing or disagreeing with an issue and defend your position with evidence.
A thesis statement that makes your view on the issue absolutely unmistakable should appear somewhere in the first paragraph.
Don’t worry about being too obvious or even leading off with your thesis.
In general, what you need is to be able to transition to your next point at the end of each body paragraph.
Still though, it helps if you can give a fresh and more enlightened perspective (i.e.
Be sure to explain how the argument depends on these assumptions and what the implications are for the argument if the assumptions prove unwarranted.
So, basically, the two writing tasks on the GRE are complementary in that you get to formulate your own argument in the issue task and critique another's argument in the argument task.
When people study for the GRE exam, they often forget about the two Writing tasks, the Analyze an Issue Task and the Analyze an Argument Task, facing them on test day. No matter how great of a writer you are, it's important to practice these essay prompts before taking the exam.
The GRE Writing Section is a doozy, but here's a brief how-to for writing the essays.