In planning for a new library that will include a limited number of open stacks, Grand Valley State University librarians were asked to identify what materials should be reserved for the browsable shelves. To accomplish this, librarians considered user behavior by discipline, material types, shelving options and the role of core collections. This paper will discuss these issues as well as differences in how library resources are located and the impact of new discovery tools, such as Innovative Interface's Encore, Bowker’s Syndetics, and Google’s Book Search on redefining browsability. The paper will also include a discussion of resources used in this process, such as the results from our recent LibQual study, WorldCat Collection Analysis' Circulation Analysis and Bowker Book Analysis reports.