GENERATING WEB-BASED PRESENTATIONS

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1 GENERATING WEB-BASED PRESENTATIONS IN SPATIAL HYPERTEXT Frank M. Shipman III, Richard Furuta, Catherine C. Marshall* Department of Computer Science& Center for the Study of Digital Libraries Texas A&M University College Station, TX { shipman, furuta, marshall ABSTRACT Presentations frequently include material appropriated from external sources; they may incorporate tabular data from published reports, photographs from books, or clip art from purchased collections. With the growing use of the World- Wide Web to disseminate information, there is the emerging potential for a new style of presentation: one that interprets and organizes materials produced by others and published on-line. Authoring such presentations requires the analysis of the source information. However, current presentation authoring software is designed to support traditional presentations, where analysis is assumed a separate task at best supported by separate software. This paper discusses experiences with using VIKI, a system designed to support information analysis, for the authoring of such presentations. VIKI includes a spatial parser to recognize implicit spatial structure generated during analysis. This paper describes how initial experiences with use for path authoring led to VIKI enhancements, including the adaptation of implicit spatial structure recognition for the creation of presentations. KEYWORDS: Presentation Authoring, Analysis Tools, Spatial Parsing, Implicit Structure, Presentation Models, Spatial Hypertext, World-Wide Web, Walden s Paths, VIKI INTRODUCTION Creating presentations is a common activity. Teachers, scholars, and many business people spend a significant part of theu time producing materials they will use to disseminate information, ideas, and views. Different types of presentations rely on background materials taken from different sources. Teachers traditionally gather materials from textbooks and curriculum guides. Scholars reflect on published results as well as on the outcomes of their own research. Business people may use market analyses, trade Permission to make digital/hard copies of all or part of this material for personal or classroom use is granted without fee provided that the copies are not made or distributed for profit or commercittl advantage, the copyright notice, the title of the publication and its date appear. and notice is given that copyright is by permission of the ACM, Inc. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires specific permission and/or fee. IUI 97, Orlando Florida ACM o /96/01..$3.50 publications, and internal reports as the basis for their presentations. The common element of all these characterizations is that much of the information underlying the presentations is derived from paper-based sources. But this is changing. More and more newspapers, magazines, and academic and trade publications are becoming available on-line. These online resources frequently include new facilities that make them better suited for creating information-rich presentations: for example, the external information is readily accessible through full-text search and alternative indexing schemes, and document components are easy to reuse, given their manipulable electronic representations. Information services like Yahoo and OpenText are examples of the growing number of businesses providing better on-line access to information. Professionally generated and edited information is becoming available as the World-Wide Web is commercialized. Many newspapers, magazines, and edited academic journals now have on-line subscription services. Of course, the Web is also a source of unedited opinions, conjecture, and gossip. How does this ready availability of external sources affect the needs of and possibilities for presentation authors? Most presentation software, such as Microsoft PowerPoint, Aldus Persuasion, or Adobe Premiere, exists as stand-alone applications. This type of software assumes that an author creates a self-contained presentation in which the content is produced strictly in service of the presentation itself. But the growth in on-line information resources suggests the development of new presentation genres, e.g., forms that draw on materials from external sources and reuse content in new, unanticipated contexts. One alternative model for presentations that we have been investigating generalizes Zellweger s directed paths [7] * Author s current address is: Xerox PARC, 3333 Coyote Hill Road, Palo Alto, CA Phone: (415) , 71

2 and Trigg s guided tours [6]. As originally defined, a directed path provided the means for guiding a reader s traversal along a path of components extracted from a set of documents or an existing hypertext network. The ordering of components on the path is not constrained by the structure of the source documents -- in other words, the components do not have to follow the temporal orderings of the source. The directed path defines a meta-structure that is layered on top of the underlying documents existing structures. This work is also reminiscent of Vannevar Bush s vision of a scholar blazing trails through reference materials in a memex [1]. The trails that Bush describes are coherent linear paths through collected materials, with possible digressive side trips. Rather than emphasizing the expressiveness of the path mechanism as is the focus of Zellweger s and Trigg s subsequent work, Bush describes a trail as analogous to gathering together physical items from widely separated sources; having simple mechanisms for flipping through the materials and commenting on them; and being able to transmit this annotated linear trail to a colleague. Walden s Paths, our variation of a directed path facility, supports the presentation of an annotated linear path of Web-based information [5]. In these presentations, the author creates a list of Web pages and associates annotations with them. By adding some text or other annotations to the content of a Web page, the path author may provide a rhetorical structure to the path as a whole, create transitions to fill in gaps between pages, and emphasize particular aspects of the materials. The goal of Walden s Paths is to allow teachers to incorporate Web-based information into their curriculum. Creating a Web-derived presentation for students is different than creating a presentation for a conference or other professional presentation. Most notably, educational paths typically take information authored by others and present it within a new context. Authoring such a path is then a combination of locating relevant Web sites, selecting which materials to include, and creating the context in which the materials will be presented to the students. Constructing coherent paths of this sort involves many activities outside the scope of standard presentation software. Path authors must engage in information discovery, validation, and management. For this reason we have been investigating the use of VIKI, a system designed to support information analysis [3], for the new task of authoring paths. In this paper we first will discuss some of our early experiences with the authoring of Web path presentations within VIKI. Then we will describe VIKI in more detail and the extensions made to VIKI to better support this type of authoring process. We focus briefly on how VIKI S recognition of implicit spatial structures can aid in the authoring of presentations. We conclude with a discussion of the initial experiences with the modified system, some lessons learned, and topics for future work. INITIAL EXPERIENCES WITH PATH AUTHORING In the course of our work on the Walden s Paths mechanism we have gained experience with authoring Web-based presentations. This experience shows that path authoring is a complex task which includes: locating promising Web sites, browsing and evaluating materials at these sites, selecting information elements for use in the path, developing an outline for the presentation, placing pages within the sections of the path, and writing the introductory text and annotating the pages. Not all of these activities occur during every authoring task nor is the list above intended to imply a strict sequence of actions. Rather, an authoring process may require many iterations through these commonly identifiable subtasks. In determining if a page is to be included in the path and the role it will fill, the path author must decide whether the informational content is appropriate for the presentation. One common consideration for appropriateness is accuracy. When it is difficult to assess the content accuracy, the information source may help determine its validity. Information from government laboratories, on-line editions of journals, and newspapers are apt to be treated differently from information from a political party or special-interest group. Considerations such as these require analysis as well as synthesis. Current tools for the Web, especially browsers and search engines, focus on the act of locating information and getting back to it once it has been found (for example, through bookmarks). Current bookmark organization tools support a limited expression of the interpretations resulting from a user s analysis -- usually through the use of folders or similar mechanisms supporting classification hierarchies, but these tools do not support the process of analysis. In addition bookmark lists generally are not intended to aid in the public task of information presentation. We have been building VIKI, a spatial hypertext system to aid the analysis of information [3]. Spatial hypertext relies on proximity and other patterns of visual attributes to show relationships and linkages; most hypertext mechanisms, like those supported on the Web, rely on point-and-click traversal. For example, in the simplest case, two adjacent nodes in a spatial hypertext may be said to be linked. Other affordances of space are used to define different kinds of hypertextual structure (like hierarchies and composite nodes). VIKI provides a hierarchy of two-dimensional spaces, called collections, for organizing symbols that represent information objects. Symbols may point to information objects that are stored in VIKI S own database, or symbols may point to external information like Web pages. This ability to organize and interpret external materials is crucial to the application described in this paper. 72

3 Figure 1: Use of VIKI to collect information for a Web-based presentation on endangered species in Texas. Experiences with VIKI have shown that users find the arrangement of information in space to be a natural method of describing the evolving interpretations that are part of analysis. Because of the need to collect and analyze Web-based information during path authoring, VIKI was used during the authoring of several paths. VIKI s facilities for capturing, organizing, and interpreting information are well matched to the initial stages of path authoring outlined above. In these initial uses of VIKI for path authoring, users built lists, outlines and similar structures within VIKI spaces to represent the final path of information. Figure 1 shows one such layout generated during the creation of a path about endangered species found in Texas. The left side of the figure, labeled Web Sources, shows references to Web pages collected by the author as being potentially of use within the path. The right side of the figure, Path for students, contains labels representing an outline for the presentation and the Web page references placed within the outlined subsections. At the time this information was collected and annotated, there was no mechanism for turning the organization of symbols in a VIKI space into a final presentation. After using VIKI to locate, interpret, select, and order information for a path, the author had to move into another interface to generate the path that would be used for presentation. Obviously, a more seamless connection between VIKI and the path presentation mechanism was desirable. In an ideal situation, VIKI would produce the path representation used by the presentation mechanism, but this was not directly possible. The VIKI users were not specifying an explicit path within- VIKI, but creating a spatial layout that was used to indicate implicitly, at least to the author, a linear sequence of elements for the path. Layouts such as that in Figure 1 suggested the need to take a layout of information within VIKI and have the system 73

4 determine a linear ordering of the constituent items. Furthermore, in this early case, not all the objects within a structure were meant to be pages on the path; some were intended as labels identifying subsections or notes the author made during the authoring process, for example the darker colored labels on the right side of Figure 1. In the next section we discuss VIKI in more detail and describe modifications made to more completely support presentation authoring, including locating the appropriate materials, and turning an implicitly structured path into a realized presentation. INTEGRATING PRESENTATION AUTHORING INTO VIKI VIKI is a system designed to support information analysis. Prior experience with Aquanet [2] indicated that users found it difficult to explicitly represent their interpretations during analysis. Instead of using Aquanet s representation mechanisms to specify relations, users placed related information objects next to one another in familiar spatial patterns like lists and stacks. VIKI was designed to facilitate and enhance this use of spatial arrangement during analysis,. Basic VIKI Hypertext, in its most general sense, allows content (text or other media) to appear in multiple contexts. In most hypertext systems, including the World-Wide Web, this is accomplished by providing nodes or pages of information which can be accessed from different through different navigational links. Experiences with the use of node-andlink hypertext led to the development of the spatial hypertext model instantiated in VIKI [3]. VIKI provides users with the ability to place and move information symbols in a set of two-dimensional spaces, called collections. Symbols can be assigned visual properties such as color, shape, and border width using an interface similar to the kind associated with a simple graphics editor. These visual properties can be used to indicate something about the information, i.e., red rectangles are from a particular source, or a wide border indicates a good article. The symbols point to information objects, which contain the actual content. These objects may be semi-structured -- an object may contain a set of textual attribute/value pairs. Several symbols may point to the same underlying information object, allowing the same object to be placed in multiple spatial contexts. Objects may be given an object type, which specifies a set of attributes for the object and a set of visual properties for the symbols pointing to that object. As an example, the object type book might have the expected attributes title, author, publisher, and synopsis, and commonly be presented as symbols with red rectangles with thin borders. Both the set of attributes and the visual properties defined by the type are defaults that may be modified for individual objects and symbols of that type. Some objects of type book could have an additional editor attribute and no value for author. The visual appearance of symbols pointing to the same object may be different, so one symbol representing a particular book object might be blue with thick borders even though all the other symbols for the same object follow the default for objects of type book. VIKI S two dimensional spaces are called collections. Collections may contain other collections, creating a hierarchy. VIKI users may navigate into (or maximize ) a collection -- causing that collection to take the full space of the VIKI window -- by double-clicking on the border. Double-clicking on the border of a currently maximized collection causes the collection to go back to its normal size. To view the contents of information objects, users doubleclick on the border of an information symbol. For objects whose contents are stored in VIKI, this opens a viewerl editor containing the information. Objects may also point to information available via the Web. When a user selects such an object for viewing, VIKI launches a Web browser (currently either NCSA S Mosaic or Netscape s Navigator depending on the user s preference) to display the information. When people are performing analyses in VIKI, they collect information, and organize it within the space to reflect their understandings. A study of common spatial patterns generated in this type of analysis task in other computational and non-computational settings indicated that a small set of primitive spatial structures were common to many of the resulting arrangements [4]. VIKI uses a heuristic spatial parsing algorithm to identify structure implicit in the layout of information symbols based on these common structures. The four basic structures that VIKI recognizes are stacks, lists, composites, and heaps (shown in Figure 2). Stacks are overlapping objects of a uniform type. Lists are horizontally or vertically aligned objects of the same type. Composites are repeating patterns of objects of differing types aligned in repeating patterns. Heaps are overlapping objects of differing types. Thus, the characteristics used to recognize structure are overlap, alignment, and object type. a Stack List Heap 0 Composite Figure 2: Diagram of spatial structures recognized in VIKI. 74

5 Figure 3: Black dots show the selection extension resulting from four subsequent mouse clicks on the structure from Figure 1. By reapplying the basic recognition algorithms to the recognized structure, a hierarchic parse of the spatial layout is generated. For example, VIKI can recognize lists of composites which themselves contain lists, such as the structure on the right side of Figure 1. VIKI uses this recognition in two ways: to support access to the implicit spatial structures, and to aid in the use of the VIKI data model. Access to recognized structures is provided through hierarchic click-selection, which is the spatial equivalent to the selection extension found in most text editors and word processors. Each click on an information symbol causes the selection to be extended to the next higher level in the spatial parse tree. Figure 3 shows a series of selections resulting from four subsequent clicks on a symbol within the structure on the right in Figure 1. The structures in this example are lists of sections that defihe a complete path. Each section is itself a list of objects, each referring to a Web page. Thus the first click selects a single object; the second click selects the list of objects in that segment of the path; the third click selects the section (including the label); and the fourth click selects the entire path. was common to path authoring practice, we added a Websearching interface to VIKI. Figure 4 shows the current interface for searching the Web. Users enter the text to search for and specify whether the terms in the text are to be considered as part of a boolean and, a boolean or, or a phrase query. Additionally, the user specifies the maximum number of results to be returned. Once the user executes the query, the system communicates with a publicly-available on-line search engine -- currently the user may choose between AltaVista and OpenText. A VIKI object is created for each of the Web pages returned by the search engine and symbols referring to these objects are displayed in a new collection. Figure 5 shows the initial results of such a search. Users may browse their query results, categorize content or note other attributes of the retrieved materials by changing the visual properties of the symbols, and select and organize VIKI also uses the spatial structure recognition to suggest new collections and composites, to help manage space, and to provide graphical macros for the creation of common symbol layouts. This assistance is only provided upon the user s request. Enhancements for Presentation Authoring As the experiences described earlier indicate, this basic version of VIKI, with the features just described, was a useful tool for the initial stages of path authoring. But the experience also indicated that VIKI could be enhanced to better support the process. Path authoring invariably relied on the use of Web-based search engines to find the appropriate Web pages and sites. Path authors used their Web browser to search and browse the Web and copied the URLS of desired pages from the Web browser into VIKI. After we observed that this activity Figure 4: A user searches for twenty Web pages that include the phrase spanish civil war. 75

6 There are two high-level choices that users must make to determine which objects will be included in the presentation; they make these choices in the presentation generation dialog shown in Figure 7. First, the user specifies whether the system should use all of the objects in the currently maximized collection or only those currently selected. Because VIKI s spatial structure recognition can be used to easily select specific structures from within a collection, users are able to define paths with little overhead from interaction. Figure 5: A collection containing the results of the search. this information in the workspace. Figure 6 shows an example of the final arrangement developed using the results of the previous search. Creating a spatial representation of the presentation, and adding introductory or explanatory text to the individual Web pages included in the presentation is performed using standard VIKI functionality. Once a user is satisfied with the content, a presentation may be created from a layout and saved as either a VIKI or a Walden s Paths presentation. Creating a VIKI presentation results in a new VIKI object and symbol that when viewed (by double-clicking on the border as with other objects) opens the VIKI presentation viewer. Creating a Walden s Paths presentation generates a textual file that can be directly interpreted by the Walden s Paths server. Figure 7: The user generates a presentations from the current selection. The second choice a user must make is whether the presentation should just include Web-based information (i.e., only those objects that refer to Web pages), or also include content created and stored in VIKI. Since VIKI objects are purely textual, they can be presented as HTML for Walden s Paths or using normal VIKI viewers for VIKI presentations. This way objects acting as labels for sections or the authors notes to themselves can be left out of the presentation. In Figure 7, the user has selected to use only Web objects ( objects with URL ) in the presentation so the two labels Overview and Anarchism will be left out of the final path. The spatial parsing discussed earlier provides users a way to select and manipulate the structures they have used to represent the presentation. Generation of the linear path additionally requires that the system determine a sequence for the objects. For lists, a common arrangement for a presentation, this is not an issue. But for other spatial arrangements, VIKI uses heuristics to determine if the selection or collection being used is likely to be organized in horizontal or vertical structures. Figure 6: A short path is generated from the search results. Figure 8 shows the VIKI presentation generated from the layout in Figure 7. The presentation controller can be used to go forward and backward through the path; it also displays the title and any introduction or annotation to the 76

7 SPAM.W REVOLU710N OF 1936 n m.+ 0., s im A& A& E.Maco,,hm,,.!m6.,,-,,.,. - s.- -.,..,.,...., hd.mec., q.+ *, a+.. d.. ~,m,m,. -=,= &., d.d,,*. -,>-7 % =$ ---e,--,+. c.--!-.,,, w,.,!!4,....,ctdm..... W..*.* * ,,,..... * -mcv.,!.,>.,.,,.,.,.. Jr.bc.iti. Figure 8: Resulting pages as displayed in VIM presentation. mm+sa+m+m *:!.=.,!..,...=.-..,*$,,wa m... SPANISH REVOLUTION OF 1936 m sp,d h CMI w- A b As& W- F,.:>.,!.- ~,,$. *W,=.*,,. *.. ~,s.,, - *.,.X.<...$***0*O h ,.*,. -q.!,..**... d l-d,l.h.p *..,,. J...,.,,, d!!.. -.,--...,.. w...%, ti.,,kj.., 8,-...!, J.k.!...*. ~...,,,,,,-4..M,.. *. -..,., ,., ti-. h m, ,,,,.,.,ti, m,,.!..-,.,. J.L d., d,...,,,.w,, -w,*.,.,..,..,....*,.. -.,.-,.!,.-...,,,. 4-.*..! -.i,., c.4.4.4, mm.., r % ,,.!,..,--- d *.,.,.,. me., n.n,bti Figure 9: Resulting pages as displayed in Walden s Paths presentation. page content. The information is displayed either in the standard VIKI text viewer or in a Web browser, depending on the content of the object. Figure 9 shows the same presentation in Walden s Paths. In this format the path server puts the control buttons and introductory text at the top of the page, with the actual Webpage below. The content from VIKI objects included in the presentation are provided as text. These presentations are displayed using a standard Web browser (Netscape in this example) and can be made available over the Web. Using these two displayers as examples, it is easy to imagine how presentation materials might be gathered, interpreted, and organized within VIKI, taking advantage of its support for analysis, then exported to any of a number of slide show systems. DISCUSSION AND FUTURE WORK Analysis is a necessary part of creating presentations from Web-based material. Gathering, evaluating, interpreting, and organizing the Web-derived materials are essential to reusing this sort of appropriated content. ~us, integrating analytic tools like VIKI with presentation authoring tools will better support the authoring process. Experience with VIKI and prior systems shows that analysis proceeds through a process of gradual understanding. VIKI provides users a way to express their hunches, intuitions, and evolving interpretations through spatial arrangements of information objects. A heuristic parser of the spatial arrangements helps users work with their spatial structures. To enhance this generalpurpose recognition facility, we have added several new heuristics to aid in the necessary linearization of spatial layouts for presentations. Users interact with the recognized structures and dialog boxes to determine which objects are included in the presentation. Currently, each object included in the presentation results in a page or slide in the presentation. Future work should provide users with the ability to specify that labels to sections of a presentation (such as those in Figure 1 and Figure 6) should be included as context on each page in that section. The approach reported here could be used to target a wide variety of different presentation systems, with the same VIKI representation used for each. Adjustments to the VIKI recognition algorithm can be used to support of the special 77

8 characteristics of different systems. Generalizing the means to recognize new structures and alternative uses for the resulting structures is a topic for future work. Our initial experiences using VIKI to author presentations resulted in layouts like that shown in Figure 1. Such structures are recognized by the spatial parser and, using the new functionalist y to define presentations, these structures can be turned into VIKI or Walden s Paths presentations. While our original goals were motivated by the work that teachers do in designing World-Wide Web presentations for students, we believe the growing availability of information on the Web will lead to similar uses of appropriated information within academic and business presentations. REFERENCES [1] Bush, V. As We May Think. Atlantic Monthly, July 1945, [2] Marshall, C.C., and Rogers, R.A. Two Years before the Mist: Experiences with Aquanet. In Proceedings of European Conference on Hypertext (Milan, Italy, November 1992), ACM Press, [3] [4] [5] [6] [7] Marshall, C. C., and Shipman, F.M. Spatial Hypertext: Designing for Change. Communications of the ACM, 38, 8 (August, 1995), Shipman, F. M., Marshall, C. C., and Moran, T.P. Finding and Using Implicit Structure in Human- Organized Layouts of Information. In Human Factors in Computing Systems, CFZI 95 Conference Proceedings (Denver CO, May 1995), ACM Press, Shipman, F.M., Marshall, C. C., Furuta, R., Brenner, D., Hsieh, H., and Kumar, V. Creating Educational Guided Paths over the World-Wide Web. In Proceedings of Ed-Telecom 96 (Boston MA, June 1996), Association for the Advancement of Computers in Education, Trigg, R.H. Guided Tours and Tabletops: Tools for Communicating in a Hypertext Environment. ACM Transactions on O@ce Information Systems, 6, 4 (October, 1988), Zellweger, P.T. Scripted Documents: A Hypertext Path Mechanism. In Proceedings of the ACM Hypertext 89 Conference (Pittsburgh PA, November 1989), ACM Press,