"The goal of this book and of the Marriage Checkup (MC) program in general is to do for marital health care what regular checkups have done for dental health care: provide a means for effectively promoting lifelong relationship health. Although the research continues to evolve, the bulk of the current findings suggest that at best cohabitation has no beneficial effect on later relationship health and at worst is associated with higher divorce rates. In short, as preventive medicine, cohabitation is snake oil--couples who think that cohabiting is a sort of trial run to reveal whether or not the relationship will become a good marriage have false expectations. However, young people and people in general are actively looking for something to help them address their fear of the divorce statistics and their legitimate concerns about long-term relationship health. I believe that the MC has the potential to legitimately and effectively address people's desire to actively protect and promote their long-term relationship health. My hope is that our ongoing research efforts will continue to support and improve on the effectiveness of the MC and that ultimately the MC, as a yearly practice over the life of a relationship, will take the place of months or years of precommitment cohabitation as the thing to which people turn to take good care of their relationship health In this book, you will find a guide to effectively conducting regular relationship health checkups in the service of promoting lifelong relationship health for all committed long-term couples--married or not"--Preface.