Coal workers' pneumoconiosis is the leading cause of death due to occupational illness among U.S. coal miners. This disease is caused by miners' exposure to excessive levels of respirable coal mine dust. A personal dust monitor (PDM) has recently been developed to provide near real-time feedback to miners regarding the level of respirable coal dust in the air they breathe. This report documents coal miners' reactions to this device and how they make use of the information it provides. It summarizes a field study by the NIOSH that documented the opinions of 30 miners at 4 underground coal mines concerning the use of PDMs.