The use of schematic knowledge about sources in source monitoring

Source monitoring refers to mental processes leading to attributions regarding the origin of information. We tested Johnson, Hashtroudi, and Lindsay's (1993) assumption that prior source-relevant knowledge is used in some source-monitoring tasks. In two experiments using different domains of schematic knowledge, two sources presented information that was expected for one source and somewhat unexpected for the other. In a later source-monitoring test, participants decided whether items had been presented by Source A, by Source B, or were new. The results of both experiments show that source identification is better for expected items than for somewhat unexpected items. Multinomial modeling analyses revealed that when participants do not remember the source of information, they guess that it was presented by the expected source. These results provide evidence for the claim that source monitoring can be based on prior knowledge and support a guessing hypothesis.