"Why Are You Doing This?" Identifying Lifeloggers Motivation and Behaviour in Order to Improve Simulated Search Tasks.

Abstract

A lifelog is a unified digital record of the life of one person. Lifeloggers continuously capture personal data in a multi-modal manner to expand their digital record. An example of such data is lifelog images. These images are captured continuously using body cams and stored for future use. Despite the increasing popularity of lifelogging, it is unknown why people practice it, how they use their data, and how they search through it. These knowledge gaps must be filled to support future work for the development of lifelog search and storage systems. Academic competitions such as the Lifelog Search Challenge, where researchers gather to evaluate their lifelog systems via simulated search tasks, would highly benefit from answers to these questions. This research addresses these issues in a series of surveys and interviews with end users and researchers. In particular, the behaviour and needs of lifeloggers are researched via online surveys. Options for simulated search tasks are researched via online surveys, semi-structured interviews, and a review of academic events. Despite a rather low response rate for the online survey for lifeloggers, the results indicate that their main motivation is fun, they use their data for reminiscence, they want searching through their data to be easier, and they search for both specific images and other information. The online surveys and interviews with lifelogging researchers and event organisers identified numerous potential improvements for evaluation of search systems: the data set should be expanded with more data and more lifeloggers, the focus should be laid more on the novices that test the systems, the variance caused by the novices should be decreased, the query descriptions should be made less ambiguous, and a second search task should be introduced. The combination of the information about the needs of the lifeloggers combined with the insights gained from the lifelogging researchers confirms that the research in this field is going in the right direction and provides concrete aspects to improve it.