Webs of Workspaces Michael Christensen1, Rüdiger Lainer2, Preben Mogensen1, Ina Wagner3, Peter Ørbæk1 2 3 Dept. of Computer Science Architekturbüro Lainer Vienna Univ. of Technology University of Aarhus, Reisnerstrasse 41 Argentinierstrasse 8 IT-Parken, Aabogade 34, A-1040 Wien, Austria A-1040 Wien, Austria DK-8200 Aarhus, Denmark
[email protected] [email protected] {toby, preben, poe}@daimi.au.dk 1
ABSTRACT
This paper presents a prototype of a cooperative virtual environment supporting cooperation through the materials being worked upon. The paper focuses on capabilities for creating flexible structures of materials as affordances for effective cooperation and awareness. At the core is the notion of workspace, as derived from ethnographic studies of architects’ work practice and their ways of assembling materials in support of ongoing work. The Manufaktur provides a tailorable 3D interface and a series of generic mechanisms to support the distributed nature and complexity of design work, the need for overview, and the visual character of materials and arrangements of them. The mechanisms - the permanence of workspaces, document-objects, webs of workspaces, templates, implantations, behaviours, etc. – have been developed in close cooperation with the architect-users. Keywords
Work practice, architecture, collaborative virtual environment, structuring mechanisms, webs of workspaces. INTRODUCTION
The Manufaktur is a 3D environment for assembling and viewing materials ‘in context’ in the form of workspaces. Our notion of workspace derives from in-depth ethnographic studies of landscape architects’ and architects’ work practice and their ways of assembling materials in their physical environment in support of ongoing work (in this paper we focus on the architects). A workspace contains an assembly of related materials ‘in context’. This context may be a whole project or a task or some ‘theme’. Building and sustaining relationships between materials and the people who are associated with them, is crucial for work which is highly complex (in terms of parameters and materials to be held present), cooperative, and distributed, with a fluent mix of tasks and people. Architects in their everyday work construct these relationships primarily through spatial links, the placing of
materials in close vicinity to each other or in a specific spatial configuration such as stacks, post-its, layers of transparent paper, folders, etc. And they use the visual qualities of the material itself – plans, sketches, images, scale model, etc. – for expressing, developing, detailing, communicating, and presenting evolving pieces of work.
Figure 1: Assemblies of materials The Manufaktur has been inspired by architects’ use of workspaces and by the visual character of their working materials and assemblies of them. Although not a substitute for the richness of a physical environment and the diversity of tangible materials it contains, a 3D digital environment such as the Manufaktur can help overcome some of the constraints of a physical workspace, and it offers additional affordances. The 3D user interface enlarges screen space, enabling users to have many materials open at the same time, to pull some to the front, while those in the back remain visible. In this paper we explore some of the structuring mechanisms that might help a cooperative ensemble, as formed by an architectural office and its network of external consultants, clients, contractors, local authorities, etc. use the Manufaktur for their work. The basis for designing these mechanisms is our fieldwork, through which we captured some of the dynamic categorizations that are expressed in assemblies of materials on architects’ desks, the walls of their office, the folders and other materials in bookshelves. At the core is the notion to create ‘webs of workspaces’. This reflects the observation that with many people working on one and the same project a document may need to reside in several workspaces at the same time, and that the context of work is constantly changing with the task at hand, the people involved, and the progressing of ideas and solutions. Building on this notion of ‘webs of workspaces’, Manufaktur supports cooperative work in a variety of ways. Here we will primarily focus on how it supports
•
conventions of arranging and viewing materials in these spaces so that others can understand these arrangements and work with them
•
dynamic configurations of collaboration spaces and sharing materials ‘in context’
•
building collective ‘memory spaces’ that are used and grow across projects and over time
•
communicating visually to notify, draw attention to, alert, etc.
Other aspects of Manufaktur have been discussed elsewhere, e.g. basic rationale in [3], hypermedia aspects in [14] and cooperative virtual environment issues in [2]. THE MANUFAKTUR
Figure 2 shows a screen shot from a prototype of the Manufaktur. It shows an open workspace containing a set of document objects. Double clicking any of the document objects will launch the document in its application, and changes to it will be reflected within 3D Manufaktur in near real time. The objects can be sized, moved, rotated, etc; light effects may be applied; documents can be made (semi) transparent; organized into groups; and much more.
•
‘Implantations’ – objects or devices that support the customisation of the Manufaktur space to changing uses. Objects to bound a space, semi-transparent objects to define areas, lighting to indicate particular features, shadows on the ‘ground’ to provide a sense of distance, are all examples of ‘implantations’.
•
Endpoints – representation of link anchors on document-objects. By integrating and extending the Webvise [7,8] hypermedia system, we enable linking capability to parts of document-objects residing within Manufaktur.
•
Workspaces – representations of sets of objects that may be manipulated as a whole.
A 3D environment like this not only makes it possible to have many documents visible at the same time, but it also, by spatial proximity, makes it possible to indicate the (changing) relevance of a document for work-in-progress, and its relation to other objects in the space. Assemblies of documents can be given permanence and can be manipulated as a whole through the creation of workspaces. We see this as a possibility for supporting crucial aspects of design practice such as fluent relationships, flexibility to zoom into a detail and out to see the whole, to simultaneously hold present a large number of parameters and their relationships [11]. In addition to elucidating practices of creatively configuring physical workspaces, our fieldwork also shows the problematic and messy ways, familiar to us all, in which layers or archaeologies of meaningful spatial arrangements crowd in on each other. This problem can partly be avoided in the Manufaktur as a result of three features: •
Workspaces can be saved and later opened, so that there can be multiple workspaces, each targeted at a particular project or sub-project. These can be closed or minimized and later returned to, either to cope with a short-term interruption or with a longer-term break in the life of a project.
•
As document objects within Manufaktur are references to the real documents (CAD documents, Excel spreadsheets etc.), copying the references does not create multiple different document versions. In contrast to the physical world, simply copying a document object from one workspace into another allows the same document or drawing to exist in several places at once. (The well-known idea of multiple links referring to the same document is in our case implemented using COM monikers [1].
•
Through reference to other workspaces, parts of, or complete contextual arrangements can be embedded into a new context.
Figure 2: Interface of the Manufaktur The Manufaktur handles workspaces, which are sets of objects in a certain spatial order. Objects may contain a reference to a document. Thus the same document may be present in many workspaces, i.e. the same document is part of various contexts of work. Several different types of objects can populate the space: •
Document-objects - ‘live’ documents from third party 2D applications with an ActiveX document server, such as spreadsheets, drawing programs, CAD programs, etc. The documents are displayed on objects in a 3D rendered OLE/ActiveX container.
•
3D models – various 3D models may be inserted into a workspace, as artefacts to be worked with, objects providing topology to the space, iconic reminders, etc.
In contrast to other examples of using 3D spaces for collaboration, e.g. [4,6], the focus in Manufaktur is on the
materials being worked on, more than on, for example, representing the people cooperating. Likewise, Manufaktur is meant to support relatively known and not too large amounts of documents. For issues relating to cooperation in handling large amounts of relatively unknown data, see for example [13,19]. The consequence is that users can, in effect, inhabit as many ‘parallel universes’ in relation to their work as they care to create. This is a very powerful feature, but support is needed to avoid confusion and disorientation in use. Furnishing mechanisms
Workspaces may manifest themselves in various ways in the including workspace - as semi-transparent objects (like cubes or spheres) physically bounding the contained objects, ramps [15], heaps, clotheslines, three dimensional grids, etc. The workspace that has been opened will occupy the whole space in a window, and it may contain other workspaces within the larger one. A core question is how to arrange workspaces within workspaces so that users can understand this arrangement. The Manufaktur space as such is empty and open, since different activities may require different kinds of spatial design. While for some purposes, one might prefer a space that offers some structure or topography, for other purposes an unbounded, unstructured space might be preferable, which allows spontaneously arranging individual objects similar to how this is done in the physical workspace. In this sense our approach is centred on the user designing the space as opposed to the approach taken in [16]. Here the system gives the overall structure of the space (rooms with walls, floors and ceilings) from the outset, guiding both usage and spatial arrangement. Our open approach has the advantage of providing a much more flexible environment. This means on the other hand that users have to be supported in structuring the Manufaktur space according to their needs. So far, we have identified three such types of structuring mechanisms: behaviour, implantations and templates. Behaviour
Objects of different shapes can exhibit special types of behaviour. Examples of these are billboards, container objects and clotheslines. A billboard is an object in the shape of a wall (or board). It exhibits the behaviour that other objects snap and stick to the front face of the ‘board-object’. That is, when colliding with the board, objects are restrained to moving along the surface made up by the front face of the billboard. The objects snapped to the board are moved with it. A sense of gravity is simulated by demanding extra force being applied when pulling objects off the board again. An example of a container object is a semi-transparent box (or sphere or some other 3D shape) that physically bounds a number of document objects. When objects collide with the outer perimeter of the box, they are pulled into it and
they are hereafter bound to the space defined by the box, in which they may be freely arranged. Moving the containing box moves the contained objects. Taking objects out of the box is done using a technique similar to the one used for billboards. Clotheslines are a bit like grid-lines known from 2D graphics applications, exhibiting a snapping behaviour similar to billboards. They are different from ordinary gridlines in the sense that they are objects in their own right and may therefore be moved freely and angled in space. Furthermore, like the examples above, when moving the clothes-line, the snapped objects move with it. Currently only the billboard is fully supported in Manufaktur. Container objects are worked upon and an implementation of clotheslines is planned as well. Implantations
Here we have learnt from architects’ notions of neutrality and flexibility and from their uses of implantations. These are objects or devices, which support the customization of a space to changing uses. In a built environment a set of elements for creating vertical and horizontal connections and transitions, such as intermediate horizontal partitionings (e.g. movable walls), ramps, ladders may be used as implantations [12]. In the 3D Manufaktur similar objects can be used, with the additional advantages of scalability, transparency, colouring, lighting, etc. Such objects can be designated not to receive mouse events in order for them to serve as structuring mechanisms only, not interrupting normal interaction with document objects. Of course, a special mode can be entered in which implantations can be manipulated. Templates
A central part of our current fieldwork and prototyping sessions is to discuss how to furnish workspaces. Templates should be available that help people to order their workspace in ways that others can understand. We distinguish between two types of templates, arrangement templates and content templates. Arrangement templates are used for placing objects according to some predefined spatial schema. Examples might be arranging the objects in a matrix (2D or 3D), in one ore more cascaded stacks (one object placed behind the other, each object e.g. slightly more to the left and above the previous) or a circle. Application of arrangement templates has currently been implemented in the case of inserting new document objects in a workspace. However, a mechanism for applying an arrangement template on-thefly to a number of already existing objects in a workspace is also being developed. This opens up the possibility of dynamically letting the user define object behaviours. Imagine for example ‘attaching’ a specific arrangement template to the above mentioned container box. This would mean that each time a new object is pulled into the box its
position within the box is calculated according to the attached template. Content templates, on the other hand, are typically more concerned with providing skeletons for different types of workspaces and the different categories – that might be workspaces themselves – of documents that should be contained in them. There might be different templates for different stages of a project and for different kinds of projects. The architects have for example suggested a project template with workspaces for different tasks, themes and categories of files. Templates such as these can be pre-defined, tailored or self-defined. Technically such templates are easily implemented using a basic “Save As” functionality to save a workspace as a template, much in the same manner as it is for example done in Microsoft Word when saving a document as a template. This means that creating a template simply becomes a matter of furnishing a workspace with objects exhibiting behaviour, implantations and skeletons for workspaces that are to be contained within this type of workspace. An important function of templates is to make efficient use of the depth of the Manufaktur space, to provide a structure of foreground and background while preserving the possibility for flexible adaptations of this space (see Fig. 3).
Figure 4: Visualizing workspace membership To illustrate the use of proxy and workspace objects, consider a workspace containing a billboard subworkspace. The architects may want to place the current CAD plans on this billboard. The proxy object corresponds to the nail on which the billboard hangs, and ‘lives’ in the bigger workspace. The workspace object is the board itself, and the objects within the billboard workspace snap to this board. It is easy to recognize by its shape, its specific colour, and the visual quality of the documents that have been placed on it. Manipulation of the nail, e.g. moving it, will affect how the billboard workspace appears in the outer workspace Workspace membership is visualized in several ways: by spatial proximity, by colour, by naming and/or by containment. Each document object is embedded in a frame in the colour of the workspace, providing quick overview of which objects belong to a workspace. This supplements the effect of spatial grouping of the workspace members. The frame is also used to display the document title and the workspace name. Furthermore, clicking on the document manipulates the document itself, clicking on the frame manipulates the workspace.
Fig. 3: Advantages of a 3D space as compared to a 2D arrangement of documents Webs of workspaces
A workspace is the basic mechanism for creating and manipulating collections of objects. A workspace is assigned a workspace object representing its content. A workspace object has an iconic function, and it is a means of manipulating the workspace as a whole. It may in addition have a special behaviour, like the billboard. Workspaces may be referred to from other workspaces by means of proxy workspace objects.
Figure 5: Workspaces may be referred to by multiple proxies even from within the same workspace. As workspaces may in general be large and contain many objects, including them directly may produce cluttered and unwieldy workspaces. We propose to alleviate this problem by letting the proxy objects have various states of openness. If a proxy object is fully closed it is represented visually by a single, user definable, 3D icon showing only that ‘here is a reference to another workspace’. A partially open workspace is represented by two icons: one representing the proxy object and the icon for the
workspace object. A fully open workspace shows, in addition to the two icons, all the objects of the included workspace within the including workspace. Naturally, other kinds of partial openness can be envisioned. Workspaces may refer arbitrarily to each other via the proxy objects except that circular references are caught: the system forbids the complete opening of a proxy that would result in a circular reference. The state of openness of an included workspace is decided by the proxy object in the parent workspace to allow other parent workspaces to present the workspace in other states of openness. For example, if workspace A and B both refer to workspace S, S may be closed in A, but fully open in B. Interaction with both, the reference and the workspace as a whole, is supported by separating the objects for the referring proxy and the referred workspace. Moving the proxy object moves the contents of the included workspace within the including workspace. It has no effects on the referred-to workspace itself. Changing the colour of the proxy object changes only the colour of the proxy icon, whereas changing the colour of the workspace icon changes the frame colour of all the objects of the included workspace. Multiple open references to the same workspace are visualized as several synchronized representations of the included workspace. Collaboration Support
External Applications
As mentioned in the introduction, the metaphor guiding the development of Manufaktur is a collaborative workplace. The Manufaktur has a distribution architecture that enables various modes of collaboration to be realised in distributed project groups via Intranets, Extranets or the Internet. Collaborators using the Manufaktur may seamlessly move between various coupling modes, from completely uncoupled, through sharing of materials with independent viewpoints to tightly coupled camera sharing.
Networked Servers
Clients on local machine
Ole Linking
SGI Manufaktur Performer + OpenGL
PC Manufaktur Direct3D + COM
Coll a p roto borat io n col Collaboration Server
TCP/IP
ODBC
/SQL
MySQL Server
Figure 6: Distribution architecture The Manufaktur supports distributed interactive collaboration through its distribution architecture. Geometry and textures of 3D objects are stored in one or more shared relational database servers. Collaborating Manufaktur clients interact via a collaboration server used
to distribute messages about object updates among session participants. Fig 6 depicts the distribution architecture. A Manufaktur client enters a collaborative session by subscribing to events from one or more workspaces on the collaboration server. Whenever the client modifies a database object, it notifies the collaboration server about what was changed. Object data are not distributed through the collaboration server; they are shared via the database server. However, while moving around 3D objects in realtime, coordinates are not committed to the database until the object is released. Instead, the object coordinates are distributed through the collaboration protocol, as this is vastly more efficient than going through the database. As each Manufaktur client could be working on several workspaces on several databases at once, all collaboration messages contain the name and port of the database server, the database and table name, and the user name of the sender. Sending this information in each collaboration message while interacting in real-time would require several hundred bytes per message. At frame rates of, say, 60 Hz a simple movement of an object could require a data stream from a single client of as much as 100 kbps. And the collaboration server would then replicate this data stream to all the participants in the session. To improve interactive response times as well as scalability, the collaboration protocol uses differential messaging to compress protocol messages. Collaboration messages come in two flavours: reference messages and difference messages. The collaboration server uniquely identifies each client, and each client keeps track of the last reference message from each participant in the session. Difference messages contain differences from the last reference message sent, and receiving clients use their saved reference messages to reconstruct whole messages from difference messages. This technique can cut down the size of transmitted difference messages by a factor of five. Update events contain a bit mask identifying the fields of the corresponding database record that have been updated. Allowing the other collaborators to fetch only these fields from the record speeds up interaction, as large textures do not have to be reloaded unless they have been updated. As described, a central collaboration server distributes events among session participants on top of TCP/IP. The choice of TCP-based distribution originates from its ease of implementation and assured message delivery, as well as the lack of a widely deployed IP multicast infrastructure. Using IP multicast (as done in MASSIVE-2 [5]) to distribute events would be more efficient than going through a central server, but is left for future work. USING THE MANUFAKTUR
Design work is intensely collaborative. In a large building project various people work on different sections and they may be responsible for particular design tasks. Hundreds of documents are created, but only very particular selections
are relevant for individual team members, and again others for the team as a whole. Most of the internal coordination is done personally. People rush around for communicating design changes, reminding someone of important things to account for, offering explanations, helping to solve an adhoc design problem, checking a drawing, etc. A building project involves many external actors technical consultants (for construction, electricity, lighting concept, etc.), one or several clients, several local authorities, contractors, etc. Currently in the achitects’ office 22 people work on five building projects, two of them large. At the same time the office puts in many tenders for competitions where a design proposal has to be prepared quickly under high pressure. The following sections describe uses of Manufaktur for collaborative work. The examples are scenarios of use. They are grounded in extensive fieldwork, including prototyping sessions. Fieldwork material has been collected over a time-span of almost two years through participant observation of ongoing work combined with in-depth interviews. It covers a variety of projects in their different stages. Several prototyping sessions, some of them over the course of several days, have been carried out with the architects in front of the screen. These sessions focused mainly on ‘re-enacting’ recent work, populating Manufaktur with ‘real’ working materials, and discussing cooperative use. Cooperating through visual conventions
A recurrent topic in our prototyping sessions is how to furnish workspaces so that others can understand them and work with them. More specifically, there is a need for supporting people to organize their projects. Conventions are an important vehicle for cooperative work. They are part of architects’ work practice and visual culture. Their ways of representing and seeing the world are strongly tied to learned conventions of drafting and rendering [9]. The architects have developed conventions regulating how to classify materials, where to put them, how to indicate what they are, how to arrange them visibly on one’s desk so that others can find them, understand the task someone is working on, get an idea of open problems, etc. The Manufaktur provides a visual language for implementing such conventions through its implantations, behaviours on objects, templates, workspace objects, colouring, naming, etc.
Figure 7: Conventions - the ‘grid’ and ‘icons’
The form and colour of what we call workspace objects may indicate what they are used for. The icons ‘C’ and ‘Jean Arp’ (Fig. 7) have been chosen by the architects to represent ‘client’ and ‘design concept’. They stand for a particular content, allowing users to identify a workspace ‘at a glance’. A complex example of how to support conventions of arranging and seeing materials is the ‘grid’ as shown in the architect’s sketch (Fig. 7). Its design builds on fieldwork observations that point to the difficulties of coordinating the drafting of plans. A large building project progresses in stages, each requiring plans of differing degrees of detailedness, depending on the purpose. It contains hundreds of details, many of them hand-drawn, and much of the aesthetic quality and specificity of a design depends on them. While some of these details are construction-relevant and have to be ready for the construction plans, others are needed for the call for tender, and again others for the finishing. The detail of how to mount the glass parts of a façade, for example, has to be fixed and drawn at a rather early stage of a project for the construction engineer to be able to do his work on this part of the building. These kinds of ‘dependencies’ cannot be translated into a strict workflow, as so many design decisions are preliminary, placeholders for the solution that finally gets implemented [21]. To keep them in mind requires considerable experience. The grid has been conceived of by the architects as a visual interface for the set of workspaces containing plans (construction, structural, infrastructure, technical, etc.), and details. It expresses conventions of how to order the planning process in a variety of ways. It stands for ‘plans’ and provides a visual categorization scheme in the form of ‘containers’ for different workspaces. It also points to a principle of structuring the work. The interface could act as a kind of ‘follow-up-diagram’, visualizing the dependencies between these sets of plans in a simple, schematic way. From the content of each box one would be able to read at a glance how far work has progressed. With several people working on different parts, problems and layers, such a way of relating workspaces provides an overview of process and status, which helps coordinate work. With the current mechanisms in Manufaktur, the grid convention can be supported by creating a set of semitransparent boxes, e.g. individually coloured, toggled as implantations (not receiving mouse-clicks). This enables working with objects inside the boxes. The boxes could exhibit the behaviour of constraining objects to their interior. Furthermore, these boxes could be created as a workspace providing a workspace object, e.g. with an icon signifying drawings, as well as the means of manipulating the boxes in the grid as a whole.
Figure 8: Example of a ‘Grid’ workspace An important aim for the fieldwork will be to discover how users choose to configure spaces for collaboration, given such open possibilities, and how to support them in making these spaces intelligible. Currently, for example, the grid convention as a workspace with semi-transparent boxes has to be created manually. As we get more experience with these arrangements, the plan is that the system will provide a range of pre-made arrangements as well as the possibility for saving and using own arrangements as templates. Dynamic configurations of workspaces
One of the prime uses of Manufaktur in the office is for saving and sharing materials ‘in context’. Eurocity, a cinema complex, is one of the major current projects of the office. It consists of eight movie theatres, which are wrapped up by a translucent skin. The theatres are envisioned as “rocky, stony, craggy”, with a rough, grey surface. As such material cannot just be bought off the shelf, a variety of methods for producing it were investigated. A preliminary specification was worked out. A letter to the construction company together with a note described in detail the process of creating a rough surface of a specific aesthetic quality. A sample was produced and taken to the client where experiments were carried out with differently coloured light on the surface.
are to do with the inflexibility of archiving systems [10]. In the paper world of files and folders, material is filed according to a set of shared, intersubjective categories, which differ from office to office. Among the formal categories that are currently used are ‘context’, ‘design concept’, ‘consultants’ (with subfolders for each of them), ‘client’, ‘plans’, ‘product information’, ‘building regulations’, ‘planning’, ‘call for tender’, etc. The changing contexts of use of materials would require quite different, dynamic categorizations. One important possibility the Manufaktur offers is that materials can be arranged and rearranged by ‘theme’ or task. Fig. 8 shows an example of a Eurocity workspace, which has been configured for a specific task – the design of the projection cabins. Light plays a major role for the design concept, e.g., the projection cabins have been conceived as transparent light boxes. Designing the projection cabins involves selecting glass and devising a way of mounting it onto the cabins that reinforces the lighting effect. The architect in charge of this task has assembled all the relevant material in the workspace (only some of it is visible in Fig. 8). In the foreground are the relevant construction plans, construction details, a sketch of the lighting concept, and a 3D visualization of the interior with the glowing projection cabins. While searching for materials, he has inserted a reference to a workspace from another project (Pleasure Dome) into this workspace (to the left of Fig. 8). It contains images of glass, foils and membranes, together with references to the manufacturing companies. For technical information (e.g. on weight and maximum sizes), he may look into the workspace of a recently completed project, copying some documents and inserting them in his current workspace. At a later stage, he might save this temporary arrangement as a reference example for future projects on how to solve a particular design problem connected with glass and lighting.
After an interruption of almost a year and with a change of the construction company, it turned out to be difficult to reconstruct the story and the growing set of materials representing it. With the material being filed away in different folders, the context was lost. Arranging them in a Manufaktur workspace, thereby linking them spatially, would allow the architects to retrieve the story. This seems particularly relevant since new people in the office joined the project who had not been part of the process of developing a solution for the concrete surface. Moreover, this small workspace might have resided all the time in the larger Eurocity workspace, acting as a reminder of a problem in suspension as long as there was no need to solve it. This is resonant with the architects’ need to maintain things present, in an unobtrusive way, taking in ‘at a glance’, ‘recognizing immediately’. Some of the difficulties of retrieving materials such as the ones related to the concrete surface of the movie theatres
Figure 8: Included Glass workspace and billboard workspace (SGI platform) Webs of workspaces such as these support the dynamic configuration of collaboration spaces. One can envisage a mixed space in which, for example, one workspace is used by one participant, and another workspace is used by another participant, while they both share a third workspace for their joint work. Other, more peripheral
participants may overview the three workspaces by referring to them from their own workspaces. Building ‘memory spaces’
Our fieldwork is full of observations that point to the difficulties of preserving the ‘memory’ of an office. An example are ‘reference details’, problems that have been solved in an exemplary way within a project and could be re-used and adapted (such as the example of the projection cabin); a special solution that has been successfully negotiated with authorities, including the argumentation around it. Central to the work in the office is the sharing of experiences with materials such as glass or concrete surfaces with special requirements concerning e.g. colour and texture. An important aspect of this memorable knowledge is its narrative character. Such material is not just a product, but a whole story of searching and testing which may be used by others who find themselves confronted with a similar problem. The narrative form allows people to go back to earlier solutions, re-assessing the constraints and eventually take another path. The narrative is alive in people’s memories as long as they are involved in it. When a problem is solved or the project ends, it gets lost as does the material, which is archived in boxes, and partially thrown away.
Fig. 9: ‘Memory’ – qualities of building materials In the Eurocity project the search for glass for the façade took several months. The idea was to use glass of an irregular textile appearance onto which light will be projected. Images of textiles were scanned and additional properties of the material specified, as non-reflecting, easy to clean, available in 3x3m format, with particular insulating properties, affordable, etc. Different consultants were involved in this search and lots of documents were produced.
Figure 10: Referencing the workspace ‘Glass’ from two different workspaces. On the architect’s screen (see Fig. 10), two workspaces are open. The first is the workspace Eurocity, including various other workspaces (concepts, client, etc.), among them the workspace ‘Eurocity Glass’ that contains the materials, which have been accumulated in the course of this search. In the second window is a workspace ‘Glass’, which has been built as a general resource for the office, glass with special requirements being an issue in most of its projects. It contains generic information about glass (weights relative to thickness, list of manufacturers, product information, scans of important journal articles, etc.). Examples of the usage of glass in various projects, e.g. Eurocity, are included as workspaces in this general workspace ‘Glass’. This is an example of the need for supporting multiple ‘parents’ for workspaces. The workspace ‘Eurocity Glass’ is a meaningful part of both workspaces, the project ‘Eurocity’ as well as the general resource ‘Glass’. The situation is schematically depicted in Figure 11. The example also shows the strengths of the visual representation of proxy and workspace objects. The iconic representation for ‘Eurocity Glass’ might very well be a texture (the distinctive feature of the glass being looked for). In the context of the project ‘Eurocity’, the distinctive aspect of the included workspace is that it contains issues pertaining to glass, whereas, as seen in the context of the general workspace ‘Glass’, the distinctive aspect of the workspace is that it is an example from the project ‘Eurocity’. Eurocity Icon
E u r o ci t y
Glass
Glass Icon
Texture Icon
Eu rocity Glass
Figure 11: Multiple ‘parents’
Awareness and collaboration
Although the four architects that are currently involved may not take active part in all sub-projects, they need to be aware of their colleagues’ work. The work of the person working on the projection cabins may be affected by decisions concerning the thickness of the ceilings, the exact positioning of the stairs, the width of entrances, etc. A simple, non-intrusive way of supporting peripheral awareness in Manufaktur is through the use of references to other workspaces. By keeping a reference to the subproject workspace open in the background of one’s primary workspace, the architect may keep aware of changes in the sub-project. In general, though not restricted to, the Manufaktur supports collaboration and awareness through the materials being worked on more than through representations of the people involved in it. There are more explicit ways of communicating design changes and events to take into account. We have analysed in-depth how people arrange materials in their immediate physical environment. Such arrangements are not just meaningful for one’s own task, but they are mindful of the work of others [3]. Most material is on people’s desk and open for others to look at. When people know that the principal architect will come in the early morning or late at night to check work-in-progress, they leave things for him to see, or he asks them to print out particular documents for him. The possibility of viewing documents in the Manufaktur workspace, where double-clicking opens them in their host application, would make this part of the work easier. An experienced architect can check most things directly from the construction plan. Although large plans contain hundreds of minute details, s/he is able to identify problematic areas or spots at a glance. Checking plans is interwoven with ongoing work, and people use different ways of communicating their observations to others: • letters or hand-written lists of questions, to-dos, suggestions together with small sketches; placing a yellow post-it with a note on an original • plan or on a print-out of an email; • marking things to change or to check in red directly on a ‘working copy’ or signaling OK in green; drawing a ‘cloud’ around a design problem directly • on the CAD file. Further work needs to be done on additional features such as placing a post-it on a CAD drawing to communicate a design change. The main idea here is to use the possibilities of visual communication a 3D space offers, and to develop a clear visual language for this – e.g. with ‘flags’ calling for attention, ‘clouds’ standing for annotations, post-its for to-dos, different colours for how urgent something is, whether something needs to be checked, or is a straightforward OK. The above scenario mainly described offline, asynchronous collaboration, but Manufaktur also supports real-time online collaboration. The following scenario shows how some
of this support can be used. Working on the Eurocity project the principal architect often has to take the train from his office to the construction site in Salzburg: a threehour train ride early in the morning. Using a wireless connection, he may connect to the project workspace and browse through the relevant materials to prepare for the day. At the construction site the architect looks at the place for escape stairs, which have been conceived as having the side part closed, but the details have not yet been fixed. He now finds that the closed sides would constrain the space too much. Wouldn't it be better if they were transparent? The architect again connects to the project workspace and places a note: “Transparent sides on escape stairs: glass metal tissue, or …?” in the relevant workspace, with a remark to distribute to detail development. He looks into the detail plans for the stairs in order to check if the transparent solution would work, and he looks at details for escape stairs from other projects: what did they do there? Due to the desirability of reaching a quick solution, the architect phones one of his colleagues, and they enter into a discussion about the transparent stair-sides. While talking over possible solutions they might share a camera to give them a common view of their shared workspace, or maintain individual cameras, showing, pointing, drawing, etc. The Manufaktur implements a few techniques to allow a collaborator to draw attention to a specific shared object in a workspace. Objects can be selected and are then highlighted by a blue bounding box to other observers. Objects can be asked to ‘face the camera’ which triggers a short animation that turns the object to face the camera, which may be shared between users. One may also trigger an animation that makes the camera fly towards an object. Users not sharing the camera may observe this as a camera flying towards the object, whereas users sharing the camera will observe the flight from within the camera. Simply moving the object slightly has also proven to be an efficient means of drawing attention to an object. The Manufaktur does not integrate voice nor video communication, although we do recognize that communication though the material is not sufficient [17]. Extra communication channels can easily be supported by external applications and integrated with Manufaktur. DISCUSSION
There are many types of computer-support for cooperative work and each of them addresses users’ needs in a different way. The Manufaktur approaches cooperation from an angle, which has been strongly influenced by the work practice of architects, in particular the distributed nature and complexity of design work, the need for overview, and the visual character of materials and of arrangements of them. Furthermore, it is influenced by approaches stressing the potential in cooperation through the materials being worked on [18,20,22]. The Manufaktur provides a tailorable 3D interface and a series of generic mechanisms
for supporting these needs: the permanence of workspaces, document-objects, webs of workspaces, templates, implantations, behaviours, etc. A few words of caution are necessary. The Manufaktur is not intended to replace the physical workspace with its great diversity of tangible artefacts. Architects’ valuation of tangible material has partly to do with the qualities of the process – they are created in intense interactions with others, partly with the specific qualities of scale and size, colour, touch, etc. Secondly, the Manufaktur is not an archiving system and not suited for it. It offers something on top of and different from present physical and digital archives. The main advantage of the Manufaktur is that it provides an overview of assemblies of (visual) materials and the parameters they represent, thereby helping to account for the complexity of a developing project. Seeing ‘the whole thing’, being able to zoom into a detail (of a particular document) and out again, supports the oscillating between precision and fuzziness, which is crucial for design work. This paper focuses on the possibilities of creating ‘webs of workspaces’ - workspaces that may partially overlap, reside in other workspaces, and be shared in different ways. These dynamic configurations of workspaces allow a team of distributed actors multiple participation in projects and tasks. Specific mechanisms enable users to make these arrangements understandable to others. Much of individual and cooperative work is done through creating assemblies of materials. Such arrangements may not only provide a good overview, they may also be a good pointer to things that are missing, providing a strong ‘recognition’ effect for material that got lost. The spatial arrangement of fields and documents also has narrative properties and ‘tells the story’ (or history) of the project. Implicit in this approach is a particular view on cooperation, in that the focus is on cooperation through the materials being worked with and upon. Although it is recognised that this approach is not sufficient, we hope that the potential has been demonstrated in this paper. ACKNOWLEDGEMENT
We acknowledge the financial support of the European Community in Esprit LTR Project 31870 ‘DESARTE. We are very grateful to our colleagues in this project for their contributions to the ideas in this paper. REFERENCES
1. Brockschmidt, K. (1995). Inside Ole (2nd ed.). Redmond, Washington, US: Microsoft Press. 2. Büscher, M., Christensen, M., Gronbak, K., Krogh, P., Mogensen, P., Shapiro, D., & Ørbæk., P. (forthcoming). Collaborative Augmented Reality Environments: Integrating VR, Working Materials, and Distributed Work Spaces. In Proceedings of Collaborative Virtual Environments 2000.
3. Büscher, M., Mogensen, P., Shapiro, D., & Wagner, I. (1999). The Manufaktur: Supporting Work Practice in (Landscape) Architecture. In M. Kyng, S. Bødker, & K. Schmidt (Ed.), Proceedings of the The Sixth European Conference on Computer Supported Cooperative Work. 21-40. Copenhagen, Denmark: Kluwer Academic Press. 4. Carlsson, C., & Hagsand, O. (1993). DIVE -- A Platform for Multi-User Virtual Environments. Computers and Graphics, 17(6). 5. Greenhalgh, C. (1996). Dynamic, embodied multicast groups in MASSIVE-2. (NOTTCS-TR-96-8). 6. Greenhalgh, C., & Benford, S. (1995). MASSIVE: A Virtual Reality System for Tele-conferencing. ACM Transactions on Computer Human Interfaces (TOCHI), 2(3), pp. 239-261. 7. Grønbæk, K., Sloth, L., & Ørbæk, P. (1999). Webvise: Browser and Proxy support for open hypermedia structuring mechanisms on the WWW. Computer Networks - The International Journal of Computer and Telecommunications Networking, 31, 1331-1345. 8. Grønbæk, K., & Trigg, R. H. (1999). From Web to Workplace: Designing Open Hypermedia Systems. Boston Massechussets: MIT Press. 9. Henderson, K. (1995). The Visual Culture of Engineers. In S. S. L. (Eds.), The Cultures of Computing (pp. 197218). Oxford: Blackwell. 10. Kompast, M., Lainer, R., & Wagner, I. (1999). Die Wunderkammer als Inspirations- und Erinnerungsraum. In M. Faßler (Eds.), Ohne Spiegel leben (pp. 313-330). München: Wilhelm Fink Verlag. 11. Lainer, R., & Wagner, I. (1998a). Connecting Qualities of Social Use with Spatial Qualities. In N. e. a. Streitz (Eds.), Cooperative Buildings Integrating Information, Organization, and Architecture (pp. 191203). Heidelberg: Springer. 12. Lainer, R., & Wagner, I. (1998b). Offenes Planen. Erweiterung der Lösungsräume für architektonisches Entwerfen. Architektur & BauForum, 196(September/Oktober), 145-148. 13. Mariani, J., & Rodden, T. (1999). The Library Abstract eSCAPE Demonstrator. Deliverable 1.0. Lancaster University. . http://escape.lancs.ac.uk/ 14. Mogensen, P., & Gronbak., K. ((forthcoming)). Hypermedia in the Virtual Project Room - Toward Open 3D Spatial Hypermedia. In Proceedings of the Accepted for Hypertext 2000. 15. Robertson, G., Czerwinski, M., Larson, K., Robbins, D., Thiel, D., & van Dantzich, M. (1998). Data Mountain: using spatial memeory for document management. Proceedings of the UIST ’98. 153-162. San Francisco, CA
16. Robertson, G., van Dantzich, M., Robbins, D., Czerwinski, M., Hinckley, K., Risden, K., Thiel, D., & Gorokhovsky, V. (2000). The Task Gallery: A 3D Window Manager. In Proceedings of the CHI ’2000. 494-501. Amsterdam: 17. Robinson, M. (1991). Double-Level Languages and Cooperative Working. AI & Society, 5, 34-60. 18. Robinson, M. (1994). Reconstructing Understandings of Organisation. In A. Clement, P. Kolm, & I. Wagner (Eds.), NetWORKing. Connecting Workers In and Between Organizations (pp. 7-16). Amsterdam: NorthHolland. 19. Snowdon, D., Benford, B., Greenhalgh, C., Ingram, R., Brown, C., Fahlén, L., & Stenius, M. (1997). A 3D Collaborative Virtual Environment for Web Browsing.
In Proceedings of the Virtual Reality WorldWide’97. Santa Clara, CA: 20. Sørgaard, P. (1987). A cooperative work perspective on use and development of computer artifacts. In Proceedings of the 10th Information Systems Research Seminar in Scandinavia (IRIS). Vaskivesi, Finland, August 10-12,1987: 21. Tellioglu, H., Wagner, I., & Lainer, R. (1998). Open Design Methodologies. Exploring Architectural Practice for Systems Design. In Proceedings of the Participatory Design Conference (PDC’98). Seattle: 22. Wagner, I. (forthcoming). 'Persuasive Artefacts' in Architectural Design and Planning. In Proceedings of the CoDesigning. Nottingham.
