Collaborative tagging describes the process by which many users add metadata in the form of keywords to shared content. Recently, collaborative tagging has grown in popularity on the web, on sites that allow users to tag bookmarks, photographs and other content. In this paper we analyze the structure of collaborative tagging systems as well as their dynamical aspects. Specifically, we discovered regularities in user activity, tag frequencies, kinds of tags used, bursts of popularity in bookmarking and a remarkable stability in the relative proportions of tags within a given url. We also present a dynamical model of collaborative tagging that predicts these stable patterns and relates them to imitation and shared knowledge.

Search systems can alleviate the need to organize personal information by helping us find it no matter where we encountered it, what we remember about it, and even if we forget it exists. Delia wants to set up a lunch meeting at a restaurant her brother had recommended last week in an email message. She should be able to find the address using one of several organizational schemes she has developed to help her manage the vast quantity of paper and electronic information she receives every day. She knows she copied information about the restaurant into her address book, but she’s not sure of the restaurant’s name, making it difficult to look it up directly. She’s not sure whether she filed the message in a folder relating to the main topic of her brother’s email message or left 58 January 2006/Vol. 49, No. 1 COMMUNICATIONS OF THE ACM it in her inbox. since she still needs to respond to him.

The project fragmentation problem in personal information management occurs when someone who is working on a single project stores and retrieves information items relating to that project from separate format-related collections (documents, emails and favorite Web sites). This study was aimed to test empirically users ' working habits in order to shed light on the project fragmentation problem. Twenty personal computer users participated in the study. Data collection tools included an interview, screen captures and a questionnaire. Results indicate that users tend to store and retrieve project-related information items based on different formats in one project folder when the interface design encourages it. However, they store and retrieve project-related information items in different folders (documents, emails and favorite Web sites) when the design encourages such fragmentation. Two types of attempts to solve the project fragmentation problem are reviewed and a new possible solution is suggested. Author Keywords Personal information management, projects, fragmentation,

1 Personal Information Management (PIM) is an activity in which an individual stores his\her personal information items in order to retrieve them later on. In a former article, we suggested the user-subjective approach, a theoretical approach proposing design principles with which PIM systems can systematically use subjective attributes of information items. In this consecutive paper, we report on a study that tested the approach by exploring the use of subjective attributes (project, importance and context) in current PIM systems, and its dependence on design characteristics. Participants were 84 personal computer users. Tools included a questionnaire (N=84), a semi-structured interview that was transcribed and analyzed (N=20), and screen captures taken from this sub-sample. Results indicate that participants tended to use subjective attributes when the design encouraged them to, however, when the design discouraged such use, they either found their own alternative ways to use them or refrained from using them altogether. This constitutes evidence in support of the user-subjective approach as it

The personal archive is not only about efficient storage and retrieval of information. This paper describes a study of forty-eight academics and the techniques and tools they use to manage their digital and material archiving of papers, emails, documents, internet bookmarks, correspondence, and other artifacts. We present two sets of results: we first discuss rationales behind subjects ’ archiving, which go beyond information retrieval to include creating a legacy, sharing resources, confronting fears and anxieties, and identity construction. We then show how these rationales were mapped into our subjects ’ physical, social and electronic spaces, and discuss implications for development of digital tools that allow for personal archiving.

Helping computer users rapidly locate files in their folder hierarchies has become an important research topic in today’s intelligent user interface design. This paper reports on FolderPredictor, a software system that can reduce the cost of locating files in hierarchical folders. FolderPredictor applies a cost-sensitive prediction algorithm to the user’s previous file access information to predict the next folder that will be accessed. Experimental results show that, on average, FolderPredictor reduces the cost of locating a file by 50%. Another advantage of FolderPredictor is that it does not require users to adapt to a new interface, but rather meshes with the existing interface for opening files on the Windows platform.

In this paper we investigate information scraps – personal information where content has been scribbled on Post-it notes, scrawled on the corners of sheets of paper, stuck in our pockets, sent in e-mail messages to ourselves, and stashed in miscellaneous digital text files. Information scraps encode information ranging from ideas and sketches to notes, reminders, shipment tracking numbers, driving directions, and even poetry. Although information scraps are ubiquitous, we have much still to learn about these loose forms of information practice. Why do we keep information scraps outside of our traditional PIM applications? What role do information scraps play in our overall information practice? How might PIM applications be better designed to accommodate and support information scraps ’ creation, manipulation and retrieval? We pursued these questions by studying the information scrap practices of 27 knowledge workers at five organizations. Our observations shed light on information scraps ’ content, form, media and location. From this data, we elaborate on the typical information scrap lifecycle, and identify common roles that information scraps play: temporary storage, archiving, work-in-progress, reminding, and management of unusual data. These roles suggest a set of unmet design needs in current PIM tools: lightweight entry, unconstrained content, flexible use and adaptability, visibility, and mobility.

Abstract. While a number of scientific workflow systems support data provenance, they primarily focus on collecting and querying provenance for single workflow runs. Scientific research projects, however, typically involve (1) many interrelated workflows (where data from one or more workflow runs are selected and used as input to subsequent runs) and (2) tasks between workflow runs that cannot be fully automated. This paper addresses the need for recording data dependencies across multiple workflow runs and accommodating data management activities performed between runs. We define a new conceptual model for representing project-level provenance based on the notion of project histories and folders, and describe mechanisms to support this model in the collection-oriented modeling and design framework of KEPLER. Our approach allows users to conveniently organize their projects and data using the familiar folder-hierarchy metaphor, while at the same time integrating this information with detailed provenance of data products generated via automated scientific workflows. 1

Several recent initiatives aim to provide a Memex-inspired semantic desktop that would integrate with or replace our current physical and electronic desktop. For these semantic desktop initiatives to succeed, we need to consider how people organise their work and use their desktop.

People can organize information items by placing them into folders or by tagging them with labels. Over the years there has been considerable discussion on the relative merits of folders vs. labels. But there is relatively little empirical data directly comparing people’s experiences with each model of organization on comparable sets of information.. We compared participants ’ experiences organizing information with both folders and labels over time. Results indicate that each model has its strengths and weaknesses when assessed with respect to basic activities of personal information management (PIM) such as keeping, organizing and re-finding. Results afford a deeper, more detailed understanding of each model in practice. This understanding is achieved by engaging participants in an active, “hands-on ” comparison of models over a period of time. Study results point to syntheses in tool support for organizing information that might combine strengths of folders and labels while avoiding the inadvertent introduction of weaknesses from these models.