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.