We hypothesize that when clinicians review clinical data in an electronic medical record, the information needs that arise are predictable, based on a number of situational factors. Because our theory does not say, exactly, what those needs are, we are using an empirical approach (observation) to detecting and categorizing them. For each need, we can construct an "infobutton" that links the clinical data to an on-line information resource. We have constructed an Infobutton Manager to match the data being reviewed by clinicians with context-appropriate infobuttons. This paper describes how the theory, observations, and practical solutions can come together to improve clinician decision making by resolving information needs.