Waking from a Dogmatic Slumber A Different View on Knowledge Management for DL’s Workshop on Semantic Interoperability in e-Science Martin Doerr Center for Cultural Informatics Institute of Computer Science Foundation for Research and Technology - Hellas London, UK March 30, 2006 ICS-FORTH March 30, 2006 1 Knowledge Management for DLs Traditional Use Cases “There are no new research challenges in DL. There are only the ones from 30 years ago we still have not solved” (anonymous, ECDL2005) Apologies: I’ll be deliberately provocative and possibly incomplete. Don’t take me too serious. What are Digital Libraries (or more generally Digital Memories )? Information systems preserving and providing access to source material, scientific and scholarly information, such as libraries of publications, experimental data collections, scholarly and scientific encyclopedic or thematic databases or knowledge bases. ICS-FORTH March 30, 2006 2 Knowledge Management for DLs Traditional Use Cases The traditional library task: Collect and preserve documents and provide finding aids The job is solved, when the (one, best) document is handed out. “All you want is in this document”. Implementing the finding aids: Assumption: User knows a topic, characterized by a noun, or knows associations of the topic uncorrelated to the problem to be solved (e.g. “organic farming” for “host-parasite studies”.) Retrieval goal: Aggregation of like items/ nearly equivalent items, best fit. Means: Metadata, classification, (subject hierarchies and precise match with categorical and factual KOS/authorities), keyword extraction. Semantic interoperability is limited to the aggregation task: Metadata are mainly homogeneous (DC, MARC etc.), challenge is the matching of terminology (KOS). ICS-FORTH March 30, 2006 3 Knowledge Management for DLs Problems No support to solve a problem, e.g., what species is this object? No support to learn from the aggregated source, to retrieve by contexts, e.g., Which professions had the relatives of van Gogh? e.g., Which excavation drawings show the finding of this object? e.g., Which resolution had Galileo’s telescope when he observed... (in general how reliable was a scientific observation, can we correct the values found?). No support to integrate complementary information in multiple sources into new insight, e.g., Which where the clients of van Gogh’s paintings? No support for cross-disciplinary search. e.g. Ecology, ethnology and biodiversity. Biology and archaeology. ICS-FORTH March 30, 2006 4 Knowledge Management for DLs Grand Challenge DLs should become integral parts of work environments as sources to find integrated knowledge and produce new knowledge. But How ? Employing “global networks of knowledge”: Understanding of user questions, scientific discourse — expressing user questions in terms of core conceptualizations (relationships, core concepts) Virtual or physical data and metadata integration — metadata schema integration as complementary elements of a larger global schema, and not as alternative views of the same content. — mapping/merging of terminology * — matching factual data (“data cleaning”) Query systems taking into account the knowledge gaps and varying precision or abstraction levels in the integrated data — processing of “unknown” values and overlapping concepts in data and queries. * main focus of the Semantic Web ICS-FORTH March 30, 2006 5 Knowledge Management for DLs Grand Challenge Is that a dream ? “Isn’t Digital information and human knowledge is too diverse, fuzzy, case-dependent?” “Is the Semantic Web much further than AI decades before?” We regard suitable knowledge management as the key. We distinguish: 1. Core ontologies for “schema semantics”, such as: “part-of”,”located at”,”used for”, “made from”. They are small and rich in relationships that structure information and relate content. 2. Ontologies that are used as “categorical data” for reference and agreement on sets of things, rather than as means of reasoning, such as: “basket ball shoe”, “whiskey tumbler”, “burma cat”, “terramycine”. They do not structure information. They aggregate, more than integrate. 3. Factual background knowledge for reference and agreement as objects of discourse, such as particular persons, places, material and immaterial objects, events, periods, names. ICS-FORTH March 30, 2006 6 Knowledge Management for DLs Preconceptions and Solutions “Libraries should not depend on domain specific needs. Domains are too many and too diverse. DLs need a generic approach.” This seduces us to only employ intuitive top-down approaches for generic metadata schemata. As a result, when the fantasy is exhausted, research stops. We need deep knowledge engineering, generalizing in a bottom-up manner from real, specific cases to find the true generic structures across multiple domains. We need interdisciplinary work on real research scenarios. “Ontologies are huge, messy, idiosyncratic and domain dependent. Mapping is the only generic thing we can do” We are transfixed with ontologies used as “categorical data” (term lists), for which this statement is mainly true. We oversee the different character of ontologies describing “schema semantics”. The latter may pertain to generic classes of discourse, rather than to domains. They are the candidates to find generic relationships that integrate both factual and categorical knowledge in a meaningful way even for specific application. We need interdisciplinary work. ICS-FORTH March 30, 2006 7 Knowledge Management for DLs Preconceptions and Solutions “Queries are mainly about classes. The main challenge of information integration is the integration of classes (terms).” We believe this is not sufficiently supported by empirical studies. Query parameters pertain to universals and particulars. We need to systematically analyze the workflow of research work and the original research questions in each phase. We need to provide access by factual relationships (Amit Sheth), such as “georeferencing”. “Manual work is not scalable or affordable. Only fully automated methods have a chance” This seduces us to discard the quality of manual, intellectual decisions. Yet billions of people produce content manually. Wikipedia demonstrates, that the above is not true. We need to design the interactive processes and the awarding of users to massively involve Virtual Communities / Organisations in cataloguing, data cleaning and ontology development. We need semiautomatic, highly distributed algorithms. We need interdisciplinary work. ICS-FORTH March 30, 2006 8 Knowledge Management for DLs Do we talk about the same thing? “We need more reasoning!” This is true. But what sort of reasoning? And before any reasoning can be done, data must be connected, in a “global network of knowledge”. We must first clarify: Do we talk about the same thing? Requisites for a global network of knowledge: 1. A sufficiently generic global model (core ontology with the revelant relationships). 2. 3. 4. Methods to populate the network: knowledge extraction / data transformation. Theories of negotiating identifier equivalence across contexts (databases). Algorithms for global, massive, distributed, semiautomatic detection of identifier equivalence (data cleaning ) across contexts and to curate referential integrity in order to create, maintain and improve the consistency of global networks of knowledge as a continuous process (not making yet another database). And only then we can do advanced reasoning and intelligent query processing ... ICS-FORTH March 30, 2006 9 Knowledge Management for DLs Example: the core ontology ISO21127 The CIDOC Conceptual Reference Model (ISO/FDIS 21127) is a core ontology describing the underlying semantics of data schemata and structures from all museum disciplines and archives. Now being merged with IFLA FRBR concepts. It is result of long-term interdisciplinary work and agreement. In essence, it is a generic model of recording of “what has happened” in human scale, i.e. a class of discourse. It can generate huge, meaningful networks of knowledge by a simple abstraction: history as meetings of people, things and information. It bears surprise: more effective metadata structures, and linking schemes can be created from it. ICS-FORTH March 30, 2006 10 Knowledge Management for DLs Example: History as Meetings of People.. t Brutus Caesar’s mother coherence volume of Caesar’s death Caesar Brutus’ dagger coherence volume of Caesar’s birth ICS-FORTH March 30, 2006 S 11 Knowledge Management for DLs Example: …Things and Information t coherence volume of second announcement Victory!!! coherence volume of first announcement other Soldiers 2nd Athenian Victory!!! 1st Athenian runner coherence volume of the battle of Marathon Marathon ICS-FORTH March 30, 2006 Athens S 12 Knowledge Management for DLs Example: Meetings and Metadata Type: Title: Title.Subtitle: Date: Creator: Publisher: Subject: Text Protocol of Proceedings of Crimea Conference II. Declaration of Liberated Europe February 11, 1945. The Premier of the Union of Soviet Socialist Republics The Prime Minister of the United Kingdom The President of the United States of America State Department Postwar division of Europe and Japan Metadata Documents About… ICS-FORTH March 30, 2006 “The following declaration has been approved: The Premier of the Union of Soviet Socialist Republics, the Prime Minister of the United Kingdom and the President of the United States of America have consulted with each other in the common interests of the people of their countries and those of liberated Europe. They jointly declare their mutual agreement to concert… ….and to ensure that Germany will never again be able to disturb the peace of the world…… “ 13 Knowledge Management for DLs Example: Meetings and Metadata Type: Title: Date: Publisher: Source: Copyright: References: Image Allied Leaders at Yalta 1945 United Press International (UPI) The Bettmann Archive Corbis Churchill, Roosevelt, Stalin Photos, Persons Metadata About… ICS-FORTH March 30, 2006 14 Knowledge Management for DLs Example: The ISO21127 Solution E52 Time-Span E39 Actor E53 Place 7012124 February 1945 P82 at some time within E7 Activity E39 Actor “Crimea Conference” E38 Image P86 falls within E65 Creation Event E39 Actor * P81 ongoing throughout E52 Time-Span E31 Document “Yalta Agreement” 11-2-1945 ICS-FORTH March 30, 2006 15 Knowledge Management for DLs CIDOC CRM Top-level Entities E55 Types refer to / refine E39 Actors E28 Conceptual Objects E18 Physical Thing participate in affect or / refer to location E2 Temporal Entities E52 Time-Spans ICS-FORTH March 30, 2006 at E53 Places 16 The CIDOC CRM A Classification of its Relationships Identification of real world items by real world names. Classification of real world items. Part-decomposition and structural properties of Conceptual & Physical Objects, Periods, Actors, Places and Times. Participation of persistent items in temporal entities. — creates a notion of history: “world-lines” meeting in space-time. Location of periods in space-time and physical objects in space. Influence of objects on activities and products and vice-versa. Reference of information objects to any real-world item. ICS-FORTH March 30, 2006 17 The CIDOC CRM Example: The Temporal Entity Hierarchy ICS-FORTH March 30, 2006 18 Knowledge Management for DLs Hypertext is wrong: Documents contain links! Linking documents by co-reference Primary link corresponding to one document CIDOC CRM Core Ontology Deductions Instance of Integration by Factual Relations Donald Johanson Johanson's Expedition Discovery of Lucy real world nodes (KOS) Cleveland Museum of Natural History AL 288-1 Lucy Ethiopia Hadar Documents in Digital Libraries ICS-FORTH March 30, 2006 19 Knowledge Management for DLs Identifier Equivalence Query “Friends of a Friend” Content 2. query input: “Κώστας” output: “George” Source 2 Content Read output: find “Kostas”, guess “Κώστας” 1. query input: “Martin” ICS-FORTH March 30, 2006 Source 1 20 Knowledge Management for DLs Curating Identifier Equivalence Join across sources by transitivity of identifier equivalence local ids Content find equivalence . . . . output: “George” Source 2 Join Dyn amic li nk find id equivaL lence i n k local ids Content query . . . . input: “Martin” ICS-FORTH March 30, 2006 Source 1 match t a b l match e “Κώστας” / “Kostas” . . . . Authority service 21 Knowledge Management for DLs Conclusions It is feasible to create effective, sustainable, large-scale networks of knowledge: The CRM and its extensions seems to have the power to integrate historical knowledge in Archives Libraries and Museums. The CRM can be applied in surprisingly simple forms (CRM Core). Is the CIDOC CRM more generally applicable to e-science? Humanities collect factual knowledge. The CRM is a model of factual relationships at first. Sciences collect categorical knowledge. But we oversee the record of experimental data, which justifies this knowledge and is by far larger than the resulting categorical knowledge. Descriptive sciences already produce both categorical and factual knowledge. Thesis: the evaluation, access to and reuse of the record of experimental data of the sciences has a historical dimension: who measured what, when, where under which circumstances, with which methods, which knowledge, which care? We overestimate the relevance of domain categories, and completely oversee the relevance of the historical relationships in our scientific reasoning (I am physicist). Try the CRM, as a starting model for e-science, and see what else is needed. ICS-FORTH March 30, 2006 22 Knowledge Management for DLs Conclusions If we rethink old positions, we will find surprising new answers to “..an information model for digital libraries that intentionally moves 'beyond search and access’, without ignoring these functions, and facilitates the creation of collaborative and contextual knowledge environments.” (C.Lagoze, D-Lib Magazine 2005) But: We need a massive investment in understanding and generalizing the intellectual processes and original research questions in interdisciplinary work. We have to do research in dynamic collaborative knowledge organization forms, formal processes and algorithms that converge to higher stages of knowledge integration. The large networks of integrated knowledge to come will need continuous maintenance with new, specific social organisation forms and GRID-like resource access, and they may look very different from our current systems… (This is again a 30 years old challenge, are we closer now?) ICS-FORTH March 30, 2006 23