What is the technique Katniss uses to un-jumble her thoughts, or make things clear in her mind?

From the text:

I use a technique one of the doctors suggested. I start with the simplest things I know to be true and work toward the more complicated. The list begins to roll in my head.... My name is Katniss Everdeen. I am seventeen years old. My home is District 12. I was in the Hunger Games. I escaped. The Capitol hates me. Peeta was taken prisoner. He is thought to be dead. Most likely he is dead. It is probably best if he is dead....