Rural water systems in low-income countries often fail to deliver potable water sustainably. Reasons include socio-economic, financial, and technical challenges that are specific to the community. Improved assessment methods are critical if decision makers want to provide sustainable solutions; however, to be useful, such methods require substantial data about the complex interaction between people, water, and infrastructure. Such interaction is affected by, and in turn, affects the behavior of community members regarding water usage, resources for infrastructure maintenance, and choice of assets. Unfortunately, much of these data are not readily available, in a large part because of the site-specific context associated with each rural community. Because of the difficulty and expense in obtaining site-specific data, it is important to identify the most critical needs for field studies versus the data that can be obtained from sources such as non-governmental organizations and the general literature. This paper discuesses best practices for conducting and using focused field studies versus the general literature.