This chapter is an essay about topical relevance in the context of problem solving and decision making. It reviews the many ways in which information can be relevant to a problem, that is, assist in solving the problem. It shows how information can assist in problem recognition, definition, and reframing; can provide similar cases and analogous problems from different subject domains to spur creativity; can give the solution outright or building blocks − data and methods − for deriving a solution, and, finally, can suggest ways for assessing the solution. Through this review the chapter expands the typology of topical relevance relationships discussed in the literature; it reinforces the case that topical relevance goes far beyond aboutness and needs to be analyzed as a highly differentiated concept. The chapter provides the basis for designing an information system that supports problem solving by assembling the pieces of information needed to solve the problem and arranging these pieces in an order most useful to the problem solver. The classification of types of relevance presented can serve as a template both for directing search and for arranging search results.