The Doomsday Book

Connie Willis
How do you define a "great book"?
Technically, this is science fiction. It's a story of time travel, a contrast between the years 2048 and the 1300's;  between a time proficient in science, particularly medical science, and a time of  horrifying physical want and disease.  Between future scholarly Oxford and a medieval rural community struggling to be self-sufficient miles outside ancient Oxford.
But at it's core, this is a study of people trying to survive, and human relationships.  What happens when history stops being an academic study and becomes a personal experience?  When names carved in stone become living, breathing individuals?
I think I've mentioned in other reviews that I am coming to understand that a "great book", to me, is a book that changes the way I see or understand the world.  The Doomsday Book did that.
It doesn't surprise me that this book won the Nebula and the Hugo Awards, the top awards in the sci-fi field.
I have also read Connie Willis' Bellwether.  I enjoyed it very much.  I'm beginning to feel that if I see her name on the spine of a book, I want to pick that book up and jump in.  Wanna join me?  We might have some great discussions!