Folder Versus Tag Preference in Personal Information Management Ofer Bergman, Noa Gradovitch, and Judit Bar-Ilan Department of Information Science, Bar-Ilan University Ramat-Gan, Max ve-Anna Webb Street, Israel, 5290002. E-mail: oferbergman@gmail.com, noa.grasdovitch@live.biu.ac.il, barilaj@mail.biu.ac.il Ruth Beyth-Marom Department of Education and Psychology, The Open University of Israel, 108 Ravutski Street POB 808, Raanana 43107, Israel. E-mail: ruthbm@openu.ac.il 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 clas- sification recording software and a retrieval-habits ques- tionnaire. 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 margin- ally used for retrieval. The controlled retrieval task showed lower success rates and slower retrieval speeds for tag use. Possible reasons for participants’ prefer- ences are discussed. Personal information management (PIM) is a basic human–computer behavior in which the user stores his or her information items (e.g., files, e-mails, and web favorites) to later retrieve them. Traditionally, PIM systems provided folders for information storage and retrieval; however, as a consequence of the popularity of Web 2.0, tags also defused into PIM systems. It is widely claimed that tags have two fundamental advantages over folders: Tags enable multiple classification and eliminate the need for hierarchies. (a) Multiple Classification: In the folders method, an information item can be stored only in a single folder; however, the user may have a number of possible classifications related to that item (Dourish et al., 2000). For example, pictures from a conference in Copenhagen can be stored under “Pictures,” “Trips,” “Conferences,” or “Copenhagen.” As time passes, users may forget the choice they initially made, making retrieval difficult. In contrast, the tagging method enables users to apply any number of tags to their information item, and use any of these tags to retrieve it. (b) No Hierarchical Location: Folders may hide information items from view because they do not show items contained in subfolders (Malone, 1983). The tagging method consciously rejects hierarchies and locations. Instead, all information items are stored in a single repository and are retrieved via nonhier- archical means such as tag search, tag selection, or tag clouds. Which option is preferable when both options are avail- able and users are familiar with both? To our knowledge, this is the first research study to test this question. We con- ducted two studies: In one, the Gmail study, we first intro- duced 75 participants to the folder-labeling and tag-labeling options of the Gmail interface, waited 1 month, and then observed their mailboxes to analyze their actual behavior. In the second study, the Windows 7 study, we asked 23 partici- pants to tag all files that they used for a period of 2 weeks, then returned after 5 weeks to observe, using special soft- ware, the amount of tagging performed on new files and conducted in-depth interviews regarding the users’ behavior. In the Windows 7 study, we also compared the retrieval efficiency of the two methods using a controlled test. Theoretical Background Folder Hierarchies Hierarchical storage was first introduced to end-users in the Multics operating system in the mid-1960s. Users were Received August 12, 2012; Revised December 4, 2012; accepted December 4, 2012 © 2013 ASIS&T • Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/asi.22906 JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, ••(••):••–••, 2013