Visits to parolees and probationers by their case officers have been part of the fabric of the justice system for more than a century. But there has been little research into why these visits are effective and which components are effective. A recent Abt Global study for the National Institute of Justice analyzed home visits in Minnesota and Ohio qualitatively and quantitatively. The study found that overall field visits did seem to reduce recidivism, but some findings in Minnesota and Ohio were inconsistent. For example, in Ohio, unscheduled and scheduled visits were equally effective, while in Minnesota unscheduled visits led to significant reductions in recidivism. The study concluded that more research is needed to determine best practices for case officer visits.