Retention of autobiographical memories: An Internet-based diary study Gert Kristo University of Tilburg and University of Amsterdam, The Netherlands Steve M. J. Janssen Duke University, Durham, NC, USA, and University of Amsterdam, The Netherlands Jaap M. J. Murre University of Amsterdam, The Netherlands In this online study we examined the retention of recent personal events using an Internet-based diary technique. Each participant (N878) recorded on a website one recent personal event and was contacted after a retention interval that ranged between 2 and 46 days. We investigated how well the participants could recall the content, time, and details of their recorded event. We found a classic retention function. Details of the events were forgotten more rapidly than the content and the time of the events. There were no differences between the forgetting rates of the ‘‘who’’, ‘‘what’’ and ‘‘where’’ elements of the content component. Reminiscing, social sharing, pleasantness, and frequency of occurrence aided recall, but surprisingly importance and emotionality did not. They were, however, strongly associated with reminiscing and social sharing. Keywords: Autobiographical memory; Episodic memory; Reminiscence; Diary study; Internet. This study examines several factors influencing the retention of autobiographical memories. We will use the definition that autobiographical memory is the recollection of memories that people have about personal events that were experienced at a specific moment in time (Brewer, 1986). These memories may be impor- tant or they might concern trivial events, such as what one ate for breakfast or with whom one had a conversation yesterday. Researchers have developed various techni- ques for the investigation of autobiographical memory (Rubin, 2005). One could collect perso- nal events by asking people to talk about their lives, a method called free narrative (e.g., From- holt & Larsen, 1991). Another method is the fluency task (e.g., Howes & Katz, 1992), in which participants are given a certain amount of time to name as many personal memories as possible from a particular lifetime period. The number of retrieved memories will be compared to the number of memories from other lifetime periods. A third method is to ask people to name the most important or most vivid personal events of their lives (e.g., Cohen & Faulkner, 1988; Fitzgerald, 1988; Rubin & Kozin, 1984) or to ask them to give # 2009 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business Address correspondence to: Jaap M. J. Murre, University of Amsterdam, Department of Psychology, Roetersstraat 15  Room A.628, 1018 WB Amsterdam, The Netherlands. E-mail: jaap@murre.com This research was supported by a Cognition grant to JM and a Rubicon grant to SJ, both from the Netherlands Organisation for Scientific Research (NWO). The experiment complies with the current laws of the Netherlands in which it was performed. We would like to thank Prof. Berntsen, Dr Meeter, and two anonymous reviewers for helpful suggestions. MEMORY, 2009, 17 (8), 816829 http://www.psypress.com/memory DOI:10.1080/09658210903143841 Downloaded By: [Hokkaido University] At: 05:21 16 November 2009