Challenging Ubiquitous Inverted Files

Stand-alone ranking systems based on highly optimized inverted file structures are generally considered ‘the’ solution for building search engines. Observing various developments in software and hardware, we argue however that IR research faces a complex engineering problem in the quest for more flexible yet efficient retrieval systems. We propose to base the development of retrieval systems on ‘the database approach’: mapping high-level declarative specifications of the retrieval process into efficient query plans. We present the Mirror DBMS as a prototype implementation of a retrieval system based on this approach

Towards improved performance and interoperability in distributed and physical union catalogues

Purpose of this paper: This paper details research undertaken to determine the key differences in the performance of certain centralised (physical) and distributed (virtual) bibliographic catalogue services, and to suggest strategies for improving interoperability and performance in, and between, physical and virtual models. Design/methodology/approach: Methodically defined searches of a centralised catalogue service and selected distributed catalogues were conducted using the Z39.50 information retrieval protocol, allowing search types to be semantically defined. The methodology also entailed the use of two workshops comprising systems librarians and cataloguers to inform suggested strategies for improving performance and interoperability within both environments. Findings: Technical interoperability was permitted easily between centralised and distributed models, however the various individual configurations permitted only limited semantic interoperability. Significant prescription in cataloguing and indexing guidelines, greater participation in the Program for Collaborative Cataloging (PCC), consideration of future 'FRBR' migration, and greater disclosure to end users are some of the suggested strategies to improve performance and semantic interoperability. Practical implications: This paper informs the LIS research community and union catalogue administrators, but also has numerous practical implications for those establishing distributed systems based on Z39.50 and SRW, as well as those establishing centralised systems. What is original/value of the paper?: The paper moves the discussion of Z39.50 based systems away from anecdotal evidence and provides recommendations based on testing and is intimately informed by the UK cataloguing and systems librarian community

Collaborative memory knowledge: A distributed reliabilist perspective

Collaborative remembering, in which two or more individuals cooperate to remember together, is an ordinary occurrence. Ordinary though it may be, it challenges traditional understandings of remembering as a cognitive process unfolding within a single subject, as well as traditional understandings of memory knowledge as a justified memory belief held within the mind of a single subject. Collaborative memory has come to be a major area of research in psychology, but it has so far not been investigated in epistemology. In this chapter, we attempt an initial exploration of the epistemological implications of collaborative memory research, taking as our starting point the “extended knowledge” debate which has resulted from the recent encounter between extracranialist theories of cognition and externalist theories of knowledge (Carter et al., 2014; Carter et al., forthcoming). Various forms of socially and technologically augmented memory have played important roles in the extended knowledge debate, but the debate has so far not taken collaborative memory, in particular, into account. We will argue that collaborative memory supports a novel externalist theory of knowledge: distributed reliabilism. Distributed reliabilism departs in two important respects from both traditional reliabilism (Goldman, 2012) and updated theories such as extended (Goldberg, 2010) and social reliabilism (Goldman, 2014). First, it acknowledges that belief-forming processes may extend extracranially to include processing performed both by other subjects and by technological artifacts. Second, it acknowledges that distributed sociotechnical systems themselves may be knowing subjects. Overall, then, the main aim of the chapter is to draw out the philosophical implications of psychological research on collaborative memory. But our argument will also suggest that it may be useful to broaden the standard conception of collaborative memory to include not only the sorts of direct interactions among subjects that have been the focus of psychological research so far but also a range of more indirect, technology-supported and -mediated interactions, and it thus has implications for psychology as well

Collaborative video searching on a tabletop

Almost all system and application design for multimedia systems is based around a single user working in isolation to perform some task yet much of the work for which we use computers to help us, is based on working collaboratively with colleagues. Groupware systems do support user collaboration but typically this is supported through software and users still physically work independently. Tabletop systems, such as the DiamondTouch from MERL, are interface devices which support direct user collaboration on a tabletop. When a tabletop is used as the interface for a multimedia system, such as a video search system, then this kind of direct collaboration raises many questions for system design. In this paper we present a tabletop system for supporting a pair of users in a video search task and we evaluate the system not only in terms of search performance but also in terms of user–user interaction and how different user personalities within each pair of searchers impacts search performance and user interaction. Incorporating the user into the system evaluation as we have done here reveals several interesting results and has important ramifications for the design of a multimedia search system

Pinwheel Scheduling for Fault-tolerant Broadcast Disks in Real-time Database Systems

The design of programs for broadcast disks which incorporate real-time and fault-tolerance requirements is considered. A generalized model for real-time fault-tolerant broadcast disks is defined. It is shown that designing programs for broadcast disks specified in this model is closely related to the scheduling of pinwheel task systems. Some new results in pinwheel scheduling theory are derived, which facilitate the efficient generation of real-time fault-tolerant broadcast disk programs.National Science Foundation (CCR-9308344, CCR-9596282