Increasingly, digital libraries are being defined as collection pointers to World Wide Web-based resources rather than collections that hold the resources themselves. Maintaining these collections is challenging due to distributed document ownership and high fluidity. Typically a collection's maintainer has to assess the relevance of changes with little system aid. This paper describes the Walden's Paths Path Manager, which assists a maintainer in discovering when relevant changes occur to linked resources. The approach and system design was informed by a study of how people perceive changes of Web pages. The study indicated that structural changes are key in determining the overall change and that presentation changes are considered irrelevant. The paper is divided into seven sections. The first section is an introduction. The second presents background about this work and its motivation. Sections three and four describe the approach used and its implementation as a prototype system. Section five gives an overview of the study to better understand how people perceive changes and how to refine the Path Manager. Sections six and seven conclude the paper. (Contains 24 references.) (AEF)