Ofer Bergman
Bar-Ilan University
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Featured researches published by Ofer Bergman.
ACM Transactions on Information Systems | 2008
Ofer Bergman; Ruth Beyth-Marom; Rafi Nachmias; Noa Gradovitch; Steve Whittaker
Traditionally users access their personal files mainly by usingfolder navigation. We evaluate whether recent improvements indesktop search have changed this fundamental aspect of PersonalInformation Management (PIM). We tested this in two studies usingthe same questionnaire: (a) The Windows Studya longitudinalcomparison of Google Desktop and Windows XP SearchCompanion, and (b) The Mac Studya large scale comparison of MacSpotlight and Sherlock. There were few effects forimproved search. First, regardless of search engine, there was astrong navigation preference: on average, users estimated that theyused navigation for 56-68% of file retrieval events but searchedfor only 4-15% of events. Second, the effect of improving thequality of the search engine on search usage was limited andinconsistent. Third, search was used mainly as a last resort whenusers could not remember file location. Finally, there was noevidence that using improved desktop search engines leads people tochange their filing habits to become less reliant on hierarchicalfile organization. We conclude by offering theoretical explanationsfor navigation preference, relating to differences between PIM andInternet retrieval, and suggest alternative design directions forPIM systems.
ubiquitous computing | 2010
Steve Whittaker; Ofer Bergman; Paul D. Clough
We examine the effects of new technologies for digital photography on people’s longer term storage and access to collections of personal photos. We report an empirical study of parents’ ability to retrieve photos related to salient family events from more than a year ago. Performance was relatively poor with people failing to find almost 40% of pictures. We analyze participants’ organizational and access strategies to identify reasons for this poor performance. Possible reasons for retrieval failure include: storing too many pictures, rudimentary organization, use of multiple storage systems, failure to maintain collections and participants’ false beliefs about their ability to access photos. We conclude by exploring the technical and theoretical implications of these findings.
Journal of the Association for Information Science and Technology | 2003
Ofer Bergman; Ruth Beyth-Marom; Rafi Nachmias
In this article we suggest a user-subjective approach to Personal Information Management (PIM) system design. This approach advocates that PIM systems relate to the subjective value-added attributes that the user gives to the data stored in the PIM system. These attributes should facilitate system use: help the user find the information item again, recall it when needed, and use it effectively in the next interaction with the item. Driven from the user-subjective approach are three generic principles which are described and discussed: (a) The subjective classification principle, stating that all information items related to the same subjective topic should be classified together regardless of their technological format; (b) The subjective importance principle, proposing that the subjective importance of information should determine its degree of visual salience and accessibility; and (c) The subjective context principle, suggesting that information should be retrieved and viewed by the user in the same context in which it was previously used. We claim that these principles are only sporadically implemented in operating systems currently available on personal computers, and demonstrate alternatives for interface design.
Human-Computer Interaction | 2012
Steve Whittaker; Vaiva Kalnikaite; Daniela Petrelli; Abigail Sellen; Nicolas Villar; Ofer Bergman; Paul D. Clough; Jens Brockmeier
Lifelogging is a technically inspired approach that attempts to address the problem of human forgetting by developing systems that “record everything.” Uptake of lifelogging systems has generally been disappointing, however. One reason for this lack of uptake is the absence of design principles for developing digital systems to support memory. Synthesizing multiple studies, we identify and evaluate 4 new empirically motivated design principles for lifelogging: Selectivity, Embodiment, Synergy, and Reminiscence. We first summarize four empirical studies that motivate the principles, then describe the evaluation of four novel systems built to embody these principles. We show that design principles were generative, leading to the development of new classes of lifelogging system, as well as providing strategic guidance about how those systems should be built. Evaluations suggest support for Selection and Embodiment principles, but more conceptual and technical work is needed to refine the Synergy and Reminiscence principles.
Journal of the Association for Information Science and Technology | 2010
Ofer Bergman; Steve Whittaker; Mark Sanderson; Rafi Nachmias; Anand Ramamoorthy
A huge number of informal messages are posted every day in social network sites, blogs, and discussion forums. Emotions seem to be frequently important in these texts for expressing friendship, showing social support or as part of online arguments. Algorithms to identify sentiment and sentiment strength are needed to help understand the role of emotion in this informal communication and also to identify inappropriate or anomalous affective utterances, potentially associated with threatening behavior to the self or others. Nevertheless, existing sentiment detection algorithms tend to be commercially oriented, designed to identify opinions about products rather than user behaviors. This article partly fills this gap with a new algorithm, SentiStrength, to extract sentiment strength from informal English text, using new methods to exploit the de facto grammars and spelling styles of cyberspace. Applied to MySpace comments and with a lookup table of term sentiment strengths optimized by machine learning, SentiStrength is able to predict positive emotion with 60.6p accuracy and negative emotion with 72.8p accuracy, both based upon strength scales of 1–5. The former, but not the latter, is better than baseline and a wide range of general machine learning approaches.
human factors in computing systems | 2004
Ofer Bergman; Richard Boardman; Jacek Gwizdka; William E. Jones
Personal Information Management (PIM) is the management of information (e.g. files, emails, and bookmarks) by an individual in support of his/her roles and tasks. Although PIM is practiced daily by millions of people, a research community has never been established. This SIG aims to provide an opportunity for researchers, students and designers who share an interest in the field to meet and discuss key issues. We hope the SIG will lay the foundation for an ongoing PIM research community.
Journal of the Association for Information Science and Technology | 2013
Ofer Bergman; Noa Gradovitch; Judit Bar-Ilan; Ruth Beyth-Marom
Users’ preferences for folders versus tags was studied in 2 working environments where both options were available to them. In the Gmail study, we informed 75 participants about both folder‐labeling and tag‐labeling, observed their storage behavior after 1 month, and asked them to estimate the proportions of different retrieval options in their behavior. In the Windows 7 study, we informed 23 participants about tags and asked them to tag all their files for 2 weeks, followed by a period of 5 weeks of free choice between the 2 methods. Their storage and retrieval habits were tested prior to the learning session and, after 7 weeks, using special classification recording software and a retrieval‐habits questionnaire. A controlled retrieval task and an in‐depth interview were conducted. Results of both studies show a strong preference for folders over tags for both storage and retrieval. In the minority of cases where tags were used for storage, participants typically used a single tag per information item. Moreover, when multiple classification was used for storage, it was only marginally used for retrieval. The controlled retrieval task showed lower success rates and slower retrieval speeds for tag use. Possible reasons for participants’ preferences are discussed.
human factors in computing systems | 2012
Ofer Bergman; Steve Whittaker; Mark Sanderson; Rafi Nachmias; Anand Ramamoorthy
Folder navigation is the main way that computer users retrieve their personal files. However we know surprisingly little about navigation, particularly about how it is affected by the operating system used, the interface presentation and the folder structure. To investigate this, we asked 289 participants to retrieve 1,109 of their own active files. We analyzed the 4,948 resulting retrieval steps, i.e. moves through the hierarchical folder tree. Results show: (a) significant differences in overall retrieval time between PC and Mac that arise from different organizational strategies rather than interface design; (b) the default Windows presentation is suboptimal - if changed, retrieval time could be reduced substantially and (c) contrary to our expectations, folder depth did not affect step duration. We discuss possible reasons for these results and suggest directions for future research.
ubiquitous computing | 2013
Ofer Bergman; Maskit Tene-Rubinstein; Jonathan Shalom
Personal information management research has consistently shown navigation preference over search. One possible explanation for this is that search requires more cognitive attention than navigation. We tested this hypothesis using the dual-task paradigm. We read a list of words to each of our 62 participants, asked them to navigate or search to a target file, and then compared the number of words recalled in each condition. Participants remembered significantly more words when retrieving by navigation than by search. The fact that they performed better at the secondary task when navigating indicates that it required less cognitive attention than search. Our results also cast doubt on the assumption that search is more efficient and easier to use than navigation: Search took nearly three times longer than navigation, was more vulnerable to mistakes and retrieval failures and was perceived as more difficult on a subjective evaluation. Our results also support the folk belief that women are better than men and that younger people are better than older ones, at multitasking.
Journal of the Association for Information Science and Technology | 2014
Ofer Bergman; Steve Whittaker; Noa Falk
People who are collaborating can share files in two main ways: performing Group Information Management (GIM) using a common repository or performing Personal Information Management (PIM) by distributing files as e‐mail attachments and storing them in personal repositories. There is a trend toward using common repositories with many organizations encouraging workers to use GIM to avoid duplication of files and management. So far, PIM and GIM have been studied by different research communities, so their effectiveness for file retrieval has not yet been systematically compared. We compared PIM and GIM in a large‐scale elicited personal information retrieval study. We asked 275 users to retrieve 860 of their own shared files, testing the effect of sharing method on success and efficiency of retrieval. Participants preferred PIM over GIM. More important, PIM retrieval was more successful: Participants using GIM failed to find 22% of their files compared with 13% failures using PIM. This may be because active organization aids retrieval: When using personally created folders, the failure percentage was 65% lower than when using default folders (e.g., My Documents), and more than 5 times lower than when using folders created by others for GIM. Theoretical reasons for this are discussed.