Scientific and legal institutions share the goal of discovering the truth about real events. This important goal may be hampered, however, by certain normal and natural memory processes that occur whenever human beings acquire, retain, and attempt to retrieve information. Specifically, when individuals are presented with pieces of information, as when they witness a crime or accident, those pieces of information from different sources originating at different times can be integrated together. The phenomenon is termed semantic integration. The integration can include verbal information, cross-modality combination, complex facts from different stories, and the integration of verbal information into complex visual memories. In a 1975 study, Loftus presented college students with films of complex, fast-moving events and immediately afterward asked them a series of questions. This study revealed that the asking of misleading questions increased the likelihood that students would later report having seen a nonexistent object. In another experiment, results confirmed that information introduced subsequent to an event can appear as part of the event in recall efforts. Plausible information was most often assimilated in the subsequent relation of the incident. Several studies have shown that information can be provided to a witness in ways other than via leading questions, such as through an overheard conversation. People will accept new information more readily if some time has passed between the initial experience and the introduction of the new information. If a person has noticed some particular detail at the time of the initial event, it is somewhat more difficult to change his recollection about that detail. Two footnotes, 8 figures, and approximately 40 references are included.