Older adults not only have difficulty remembering the content of information, but they also have problems in remembering the source and context of information. The present project examines age deficits in remembering the source of information and is guided by a source monitoring framework (Hashtroudi, Johnson, and Chrosniak, 1989; Johnson, 1988a) that classifies source monitoring situations and highlights the central aspects of source monitoring processes. According to this framework, source attributions are based upon characteristics of activated memories such as perceptual detail, spatial/temporal information, cognitive operations information, and thoughts and feelings. Decisions regarding source involve evaluating the kind and amount of these attributes and may also require reasoning processes based on retrieving additional information from memory. The proposed experiments will assess the relative contribution of various memory characteristics to age differences in remembering source. Based on preliminary findings, it is expected that the greatest age deficits will occur in using perceptual information, and it is suggested that, under certain circumstances, perceptual deficits are related to a selective focus on thoughts and feelings. The experiments also examine whether older adults use different criteria than younger adults in making decisions about the origin of events, and whether age deficits in remembering source are dissociated from deficits in remembering content, as is the case with amnesic patients. We also investigate the possibility that source information may affect performance on indirect tests, although may not be accessible to voluntary recall. Finally, we will examine the relationship between "source forgetting" and "source amnesia" (Schacter, Harbluk, and McLachlan, 1984) and a possible link between source monitoring deficits and frontal lobe functioning. The findings from these experiments should help characterize the nature of age deficits in remembering source, and may also contribute to our understanding of the more general issue of age deficits in memory.