The intent of this book is to describe inventory and survey methods currently used for the first step of nonindigenous plant species (NIS) management; namely, to determine which species are present in the area of interest, and where they are. A complementary aim is to outline the decision-making process that goes into selecting an inventory or survey method. We offer a science-based approach that accepts the real constraints of managers while demonstrating that inventory and survey methods must be based on land use goals and NIS management objectives.