The purpose of the proposed research is to examine the effects of a semantically-oriented treatment on word retrieval in persons with aphasia. The planned investigations are designed to further the development of semantic feature training so that it may serve as not only a mechanism for improving disrupted lexical semantic processing, but also as a compensatory strategy during word retrieval failures. The proposed research will also address the issue of exemplar typicality (Kiran & Thompson, 2003) by examining the effects of training typical versus atypical exemplars of various categories with individuals with different types of aphasia. A series of 24 single subject experimental designs will be conducted in the context of a group design to address the following experimental questions: