I have been asked to propose a vision of what the virtual museum of the future might look like, let us say, in ten years from now. We are obviously dealing with an almost impossible guess, particularly due to my limited competence in the matter. I have, indeed, some ideas of how things should go. But it is extremely improbable that my vision will even partially match the effective developments. In order to propose a reflection about what is in urgent need, about the guidelines we should follow and the ways to establish fruitful cooperative work, I need, in any case, to define a possible trend of development and some view of its final results. And this implies formulating a long-term vision of the transition of cultural heritage in the web. This is what I have tried to do, being fully aware that mine is purely an exercise of wishful thinking.
Visibility on the web is today one of the major concerns for museums the world over. Many efforts are devoted to web presentations of Museums and their collections and of cultural heritage at large. The transition of museums in the cyberspace is still generally conceived as a linear development of traditional procedures. This means that the style and traditional conception of documentation and information tends to exhibit a strong inertia in the new medium. As a consequence of this inertia, the museum world seems still to be a long way from having fully exploited the potential of the transition in the cyberspace.
In this new dimension it becomes ever more difficult to accept the constraints which characterize the traditional activity of documentation and information. Let me schematically remind you of two of the basic constraints which are at work in the documentation strategies of the museums of the real world:

a) Catalogues are conceived as rigorously confined to the objects preserved by individual museums.

b) Objects are treated as isolated items; only limited attention, is devoted to inserting them into the cultural and social context to which they pertain, and to enhance their conceptual genesis, connections and meanings.

Let me insist upon the trend we observe in the actual scenario of transition of cultural heritage (museums, in particular) in the cyberspace and upon the inertia of traditional models of organization and of presentation. May be worth reminding that Museums, libraries and archives of the real world are the result of a process which began many centuries ago. Museums started out in 16^th century Europe as promiscuous bodies where art objects, instruments, artifacts of various nature, natural items, books and documents were intrinsically integrated and displayed alongside one another. The conceptual glue of what we would today rate as a hybrid ensemble was the exceptional character and the uniqueness of all the collected entities and the curiosity that they aroused in the visitor. Later evolution of museums, libraries and archives resulted in a process of progressive separation of objects from books and from documents.

The evolution of museums might be portrayed as a story of ever stronger specialization. First, the separation of art collections from scientific collections (during the Enlightenment). Then art collections underwent a further process of specialization with the separation of paintings (this marks the origins of the Pinacotheca) from sculpture (sculpture galleries), from drawings (print and drawing rooms) and from minor arts (decorative arts departments). The same process took place with regard to scientific collections. After their separation from art collections, specialization progressed through the division of mathematical and physical objects from natural history items; moreover, in the mid-19^th century, technological and industrial collections gave rise, under the impulse of the Universal Exhibitions, to new independent museums; later on, new institutions devoted to the preservation and presentation of bio-medical and ethno-anthropological collections were founded.
This evolution has produced a fragmentation of cultural documentation and cultural heritage according not only to disciplines, but also to the various categories of objects (books, documents, drawings, paintings etc.) and to their different material supports (canvas, marble or stone, paper, fabrics, timber, metal etc.).

This specialization and fragmentation process has placed all museums in a difficult position, when it comes to making explicit to visitors the value of the collection they preserve. The same holds true for libraries and archives.
These limitations derive from the fact that objects are presented in museums atomized and de-contextualized. This makes it almost impossible for visitors to grasp their real meaning and to perceive their importance. In order to achieve this goal it would be necessary to re-connect the object to the context from which it has been extracted.
When dedicating our energies to the digital conversion of cultural heritage, we have to avoid the mistake of reproducing the fragmentation of objects and records in different containers, and, above all, their isolation in specialized and totally irrelated structures (as museums, archives and libraries of the real world are today).
The new format of the humanities in the digital Age will have then to coincide with the re-composition of what the material history of cultural patrimony has fragmented. Once the information has been processed and transformed into a digital entity, it has no more to follow the fate of its physical support. There is thus no reason to store it according to the same systems used to preserve the object it emulates. In the digital domain there are no buildings or walls, and we are not obliged to reproduce distinctions based on the typologies of material objects or on the various nature of their physical shells.
The logical consequence of what I have been saying is that we can finally re-arrange the records which digitally mirror the real objects in a totally new orderly architecture. In this way we will introduce a radical alteration of the traditional system of managing information pertaining to the humanities and to the cultural heritage. We will thus build new hybrid repositories Hybrid not in the sense that this adjective has in the librarian jargon (where hybrid library means a combination of digital and analogical contents), but hybrid because the web repository is heterogeneously populated by a variety of different digital objects, which represent material objects, preserved in different containers.

To achieve these goals, in recent years, growing use has been made of information technology especially through the development of so-called virtual museums. My feeling is that the enormous potential of these new instruments has not yet been fully exploited.
The idea of the virtual museum which seems to be asserting itself, is, in fact, the idea of the digital clone of the real museum, accepting all of its structural features. In the digital replicas the museum's architectonic structure and rooms are reproduced with faithful realism, the lacunae in the collection are passively accepted; finally, its internal division into special departments is strictly reproduced. To have meaning and utility, the “virtual” museum - especially in the web - should rather be constructed with a radically different configuration from the ‘real’ museum. In cyberspace the real museum should constitute only the point of departure and return of journeys that are confined neither to the internal perimeter of the museum, nor to the same typology of items or the same discipline or genre to which it relates. The visitor should be permitted explorations not only of objects, but also of ideas and persons, of places and events, of books and documents, whenever this information is preserved.
The transition of cultural heritage in the cyberspace has thus to be conceived as the creation of a totally new architecture of knowledge: a meta-museum/library/archive, with no walls nor physical separations. A totally different construct from the way in which cultural heritage is arranged in the real world. In order to make this vision of the future of virtual museum to come true, the keywords and guidelines to keep in mind will thus be hybridisation (in the sense described above), re-contextualization, and systematic enhancement of the network of meaningful connections among the items of the cultural heritage.

On the sociological ground, one of the corollaries of this radically new vision of the future web of cultural heritage is that the traditional division of labour will have to be re-balanced. There is no question that in the cultural institutions of the real world (in museums, above all) curatorial concerns have played a crucial role in shaping the physical organization of the heritage. The fully understandable priority of the curatorial vision has also deeply affected the development of traditional documentation and communication strategies, with their strong selective emphasis upon the patrimony preserved in individual institutions.
In the cyberspace the documentation and communication strategies can be finally conceived independently of the curatorial priorities and vision. The autonomy of documentation activity from curatorial concerns will permit to stress the connections, conceptual similarities and relations among items of cultural heritage which in the real world are preserved in different places and containers. In the long run, this new conjuncture will produce an unheard of integration of knowledge, thanks to the enhancement of the enormous multiplicity of threads which connect the various items virtually stored in the immense repository of the web.
The vision of the web as a universal hybrid repository implies that the implementation of data be conducted in a way that avoids the risk of the user getting lost in it and allows for him to explore stored data according to multiple and effective modalities. It will be necessary, first of all, to offer the possibility of vertical exploration of collections preserved in individual institutions. But the crucial step is represented by the possibility of an effective horizontal navigation in the endless virtual shelves of the web repository.
Vertical exploration can be easily achieved and, in fact, we have it often at hand in the actual web, even if with different degrees of effectiveness. Much more challenging appears the solution of the problem of a 360 degrees horizontal navigation among the digital surrogates of cultural heritage items in the web space. In order to achieve this goal, a strong change of paradigm in the standard procedures of web content production has to be put into practice. One of the key points is obviously represented by the adoption of shared methods of classifications of the documents published on the web. We are far from having solved this fundamental problem. Today individual content providers publish in the web structured archives which can be vertically navigated. Only the adoption of common standards of classifications on the part of content providers – which is still a rare phenomenon – permit the user to some extent to navigate among data stored in different archives.
Hyperlinking, that is, interoperability among different digital archives, is guaranteed on a large scale only by search engines; that is by a third party (the other two being content-providers and users), which has no role in the content production. Search engines work from the outside, totally ignoring the conceptual structure of data that they filter. As everybody here knows perfectly well, search engines use above all statistic methods. Because of their extrinsic filtering procedures, search engines cannot guarantee content-driven search.
The actual schizophrenia between content and link providers is one of the problems of the actual web. It represents a serious obstacle to the exploitation of the web as a universal and hybrid repository of cultural heritage. We need then first of all to integrate and tune these two crucial functions. Moreover, in order to be really satisfactory, especially in the cultural heritage, links among the documents which are disseminated in the web should perfectly adhere to the representation of knowledge embedded in them.
We touch here upon a second strong limit of the hyper-linking system provided by search engines in the actual web. Search engines filter the web using words and strings, that is textual elements. But textual search is very inadeguate in order to filter conceptually coherent content in a federal digital repository, like the web.
Textual search is ambiguous; it suffers the misleading effects of word polisemia (both in queries and in answers); moreover, it is almost impossible to effectively manage the multi-linguistical character of the web; finally, it is not appropriate to represent and filter extra-textual documentation (sounds, images, audiovisual materials etc.) which constitute an ever growing dimension in the web.
Even if some of these limits can be overcome by the adoption of community multilingual controlled dictionaries, textual classification and search in the web repository remains inadequate if we look for content-sensitive linking. In fact content-sensitive linking constitutes a fundamental challenge for the development of a web of cultural heritage intended as a universal and hybrid repository to be meaningfully explored horizontally.
In order to achieve this goal we will have to shift emphasis in document description and hyperlinking from words and textual elements to meanings. It is at this very point that the semantic web – that is the central topic of our meeting – comes quite appropriately into play.
In the scenario which I have sketched of the future web as a universal hybrid meta-repository of cultural heritage, the shift from textual elements to associations based upon meanings has to be considered as a crucial step. The re-composition and re-contextualization of the cultural heritage in the cyber space implies in fact the systematic production of content-sensitive hyperlinks. These latters will be fully effective only if they are based upon semantic relationships. Ontological system of classifications, shared by the specific web community involved in cultural heritage exploitation - a community formed by subjects who are, at the same time, users and providers, clients and servers - will guarantee both the rational construction of a universal hybrid repository and the possibility of effective navigation in it.
Ontologies will serve both as content-sensitive search engines and as effective representations of the structures of knowledge embedded in the web repositories, thus paving the way for their use as tools for e-learning activity and giving the users the possibility of designing personal itineraries in the web repositories. Users will also have the chance of improving the efficacy of ontologies, by producing standardized descriptive meta-data which will become shared knowledge for the community. They will not simply access data provided by others, but will be able to create added value to be exploited by the community. Content-sensitive hyperlinking is a need strongly felt by members of the international community who work in the humanities and in cultural heritage. This need inspires also the vision of a recent initiative of the E.C., the ECHO network project.
Other speakers will focus upon the many ways in which semantic web can be exploited and the technicalities which its adoption involves.
I will limit myself to stress the strong relationship that I foresee between my vision of what the web of culture and cultural heritage should be in ten years time, on one side, and the development of semantic web, on the other. It is basically for this vision and these strong expectations that the Istituto e Museo di Storia della Scienza has enthusiastically adhered to the Mesmuses project. We have had a fantastic experience during the project period, working side by side with our colleagues of the Cité des Sciences, with Alain Michard and his team, and with the authoritative partners who have put at our disposal their deep knowledge of the structure of the semantic web and produced effective tools to put it into practice in our specific task.
We are very pleased with the outcome of the project. And we hope to have offered, as content providers (this has been our role), a fruitful contribution to the definition of the ontology structure and of the implementation tools. We have clearly perceived the enormous potential of the semantic web. For this reason we are now planning to use the tools developed by Mesmuses for restructuring our digital repositories which , up to now, have been organized according to the traditional data-base structure. We will use ontological classification to integrate and make more effectively interoperable the many digital archives which have been built in-house during the last 15 years. In particular, we are testing this new approach in two large hybrid archives: Galileothek@ and the Multimedia Catalogue of our Museum Collections.
We expect further promising developments from the fruitful interaction which has been established, thanks to Mesmuses, between content-providers and technology developers. I am confident that this cooperation will generate a continuous refinement of the ontologies and of the tools to effectively manage them and an improvement of their capacity, not simply to work as search engines, but also to represent the structure of knowledge which is embedded in web archives of cultural heritage.
The experience of Mesmuses has also permitted to isolate some problems to which we will have to pay attention in the future. I will briefly touch upon one of these problems.
If we want ontologies to be able to represent the structure of knowledge of documents in the web repository and to work also as tools which help in the creation of intelligent road maps, we have to take into account the fact that, when we deal with the representation of intellectual history documents (and particularly with the history of science items) we need recurring to flexible ontological structures. We should be able to adapt semantic grids in order to make them able to match the structure of knowledge of the web documents. I shall give you a concrete example.
Everybody immediately understands that the same ontology is not able to adequately represent the conceptions of the physical world of Galileo and Einstein. It is not simply that. The same ontological structure has serious problems in representing Galileo’s and Descartes’ conceptions of gravity and motion. For Galileo gravity is an internal tendency of all bodies to move towards the centre of the world. That is to say, a permanent and universal attribute of the body. On the contrary, for his contemporary Descartes, gravity is a force which operates upon bodies from the outside. That is to say that it is not an attribute of the bodies. To make this problem even more complex, one could add that the flexibility of ontologies is required not only to represent the structure of knowledge of documents whose actors are different and who have lived in different epochs, but also to semantically represent the structure of documents of the same author in different periods of his life.
In order to use semantic web to faithful represent the structure of knowledge embedded in web repositories of intellectual history, I thus foresee the need to have at hand more flexible ontologies, maybe through recourse to meta-statements which submit to chronological or spacial limitations the value of the monotone statements of the actual semantic classification.
I would like to go back, in my concluding remarks, to the vision of the virtual museum of the future which I sketched at the beginning of my presentation. And this in order to reinforce such a vision by stressing what I consider a fundamental precept or guide-line for the transition of cultural heritage in the web-space. That is to say that real world museums, libraries and archives must not be considered as models to be replicated in a linear way in cyberspace. I should be even more radical: the way in which cultural heritage is organized and exploited in the real world represents a negative model which must be abandoned once we have at hand the web and the digital surrogates of real objects.
The real world museums, archives and libraries tell us incomplete, fragmented and often incomprehensible stories. The items that they preserve are organized according to extrinsic criteria which do not help to catch their conceptual value and relationships: format, physical supports, typological categories, state of preservation, and so on. No major concern in the real world of cultural heritage for concepts like hybridisations, recomposition, conceptual contextualization.
In the real world the curatorial and patrimonial preoccupations have taken over the documentation and conceptual integration needs, that is the cultural and scientific exploitation of heritage.
The web dimension offers the space to operate this much demanded reunification and integration. No room is left here for curatorial concerns. No need to reproduce the multi-level fragmented landspace of the items of cultural heritage in the real world. Rather, the multi-dimensional structure of the web seems born to exalt connections, meaningful associations, conceptual relations. It would be really a pity to miss this fantastic opportunity.
In the future web of cultural heritage museums will be, at the same time, individual entities (that is representations of the real museums) and global and hybrid repositories. Global, in the sense that the items they preserve will be linked to all conceptually and/or materially meaningfully connected items. Hybrid, because those connections will not be limited to items of the same typology, or sharing similar physical supports, but will be extended to all kinds of documentation.
If the cultural heritage in the web does not look something like this, let us say, ten years from now, we will have to candidly acknowledge that the revolutionary potential of the transition of cultural heritage in the cyberspace has not been fully exploited.
Semantic web is expected to play a fundamental role in this process. Thanks to the continuous refinement of the methods and tools of semantic web, and thanks to its universal adoption, I hope that the vision of the future of museums in the web which I have proposed will prove to be more than wishful thinking.