Hypermedia Design Methods

1. Hypermedia Design Methods RMM, OOHDM

2. Design Space Usability � what Design � how Evaluation � non functional and functional Usability from the user point of view � doesn�t include maintainability, reuse, testability etc� Usability � what Design � how Evaluation � non functional and functional Usability from the user point of view � doesn�t include maintainability, reuse, testability etc�

3. Hypermedia development

4. Screen Based development Front Page Dream Weaver Emphasis on what the page looks like De-emphasis on getting the structure right Confuse file topology with information structureConfuse file topology with information structure

5. Design Methodologies & Models Information Based not Screen based Engineering for Reuse EORM HDM: Hypermedia Design Methodology RMM: Relationship Management Methodology OOHDM: Object Oriented Hypermedia Design Method

6. RMM: Relationship Management Methodology RMM developed at New York University�s Stern School of Business A methodology for the structured design of hypermedia systems A design model and a set of specified design steps Based on a combination of entity-relationship diagrams, and various concepts adapted from HDM RMM doesn�t address the entire development life-cycle Does address the critical stage of design http://rmm-java.stern.nyu.edu/rmm/

7. Usefulness of RMM Approach Taxonomy of applications based on two dimensions volatility of information degree of structure RMM best suited to a specific class of applications Not useful for for applications with low structure (e.g. literary works) Only partly useful for applications with high structure but low volatility (e.g. kiosk applications) Benefit from initial design, but not improved maintainability MOST useful in applications which have high structure and high volatility (e.g. product catalogues) Taxonomy of applications based on two dimensions volatility of information degree of structure RMM best suited to a specific class of applications Not useful for for applications with low structure (e.g. literary works) Only partly useful for applications with high structure but low volatility (e.g. kiosk applications) Benefit from initial design, but not improved maintainability MOST useful in applications which have high structure and high volatility (e.g. product catalogues)

8. RMM Design Model Relationship Management Data Model (RMDM) Used to represent, using suitable abstractions, the design of a hypermedia application Based heavily on HDM Design model provides a common notation and a basis for comparison / analysis of a design Uses ER model for the domain concepts �Slice� model for information presentation grouping Access model for navigation Slices are used to group attributes within an entity Slices are used to group attributes within an entity

9. RMM design methodology RMM has an explicit process model BUT model is very limited Method only addresses minor aspects of the model RMM focuses only on the design and implementation stages of the development process Many aspects are not within the scope of consideration of RMM Early life-cycle activities (e.g. feasibility studies, requirements analyses, planning) Late life-cycle activities (e.g. evaluation and maintenance) Project management activities RMM has an explicit process model BUT model is very limited Method only addresses minor aspects of the model RMM focuses only on the design and implementation stages of the development process Many aspects are not within the scope of consideration of RMM Early life-cycle activities (e.g. feasibility studies, requirements analyses, planning) Late life-cycle activities (e.g. evaluation and maintenance) Project management activities

10. The relevant entities and relationships in the application domain If the application is driven by a database the ER diagram might already be available Links between objects are explicit � these will form the users navigation paths If a navigational path across entities is required a corresponding relationship must appear in the ER diagram

11. RMDM ER Primitives Primitives (1) are standard Entity-Relationship primitives Entity types (multiple instance objects - similar to classes) Attributes which belong to entities are used to represent abstract or physical objects Associative relationships are used to represent domain level associations Represent information about the domain which is application independent. Primitives (1) are standard Entity-Relationship primitives Entity types (multiple instance objects - similar to classes) Attributes which belong to entities are used to represent abstract or physical objects Associative relationships are used to represent domain level associations Represent information about the domain which is application independent.

12. ER example The dashed lines represent associative relationships Solid lines (in slice diagrams) represent structural relationships.The dashed lines represent associative relationships Solid lines (in slice diagrams) represent structural relationships.

13. M-Slices Determine how the information in the chosen entities will be Presented to users Accessed by users m-Slices => presentation units => views Split entities into meaningful slices and organise these into a hypertext network Each slice groups one or more attributes of an entity Each m-slice groups attributes of collections of entities m-slices model what information is to be part of a presentation unit not how this information will actually be presented Developer determines how the information in the application will be grouped to be presented Ultimately pages will correspond to high level m-Slices. How users will access this information. Identify suitable slices (or m-slices) which collect together information from the various entities Each slice has an owner entity Each entity has a default slice Slices can be nested and aggregated - hence reused Result of this step is a set of slice diagrams Links between slices which support navigation are also identified These links are in addition to any associative relationships defined during the E-R design Links are between slices within a single entity, and represent structural links to related perspectives Relationships defined during E-R design are typically between slices from different entities and result in semantic or associative links Together the E-R diagram and the slices and links make up the structural components Defining an application schema Output of this step is an enriched E-R model, (referred to as the E-R+ diagram) Issues to consider: how should each entity be divided into slices which should be the default slice how should the slices be interconnected how should the links be labelled. (go through example in class) Simplest slices -- all the information an entity can be displayed within one window with scroll bars Or, divide information into meaningful units that can be presented as separate but inter-related wholes. Many webpages contain a collection of information from assorted "entities". Conventional RMDM only allows slices to be defined within a single entity It is not possible to model many Web pages. This is corrected by the introduction of m-Slices The �m� refers to Russian Matrjeska dolls m-Slices allow the modelling of presentation units which incorporate information from a collection of entities Important to emphasise that m-slices model what information is to be part of a presentation unit Not how this information will actually be presented m-Slices can be nested m-slices replace both the conventional slice primitive of earlier RMM, as well as the grouping construct. Read: Hypermedia and the Web - pages 485-486 The ER diagram + the m-slice diagram make up the structural components defining the application schema Developer determines how the information in the application will be grouped to be presented Ultimately pages will correspond to high level m-Slices. How users will access this information. Identify suitable slices (or m-slices) which collect together information from the various entities Each slice has an owner entity Each entity has a default slice Slices can be nested and aggregated - hence reused Result of this step is a set of slice diagrams Links between slices which support navigation are also identified These links are in addition to any associative relationships defined during the E-R design Links are between slices within a single entity, and represent structural links to related perspectives Relationships defined during E-R design are typically between slices from different entities and result in semantic or associative links Together the E-R diagram and the slices and links make up the structural components Defining an application schema Output of this step is an enriched E-R model, (referred to as the E-R+ diagram) Issues to consider: how should each entity be divided into slices which should be the default slice how should the slices be interconnected how should the links be labelled. (go through example in class) Simplest slices -- all the information an entity can be displayed within one window with scroll bars Or, divide information into meaningful units that can be presented as separate but inter-related wholes. Many webpages contain a collection of information from assorted "entities". Conventional RMDM only allows slices to be defined within a single entity It is not possible to model many Web pages. This is corrected by the introduction of m-Slices The �m� refers to Russian Matrjeska dolls m-Slices allow the modelling of presentation units which incorporate information from a collection of entities Important to emphasise that m-slices model what information is to be part of a presentation unit Not how this information will actually be presented m-Slices can be nested m-slices replace both the conventional slice primitive of earlier RMM, as well as the grouping construct. Read: Hypermedia and the Web - pages 485-486 The ER diagram + the m-slice diagram make up the structural components defining the application schema

14. Slices Slice = view on entity Dividing an entity into slices A slice will appear as a whole to the user ? Coherence and conciseness essential Choose one slice to be the head � the default to anchor links coming into the entity Faculty entity subdivided into 4 slices The head slice is is general because it is representative of the slices. Links are reflecting navigation from general to more specific information. Link labels will offer preview insight into the purpose of the link and direct sensible anchor and link labels. General slice groups attributes name, description and rank Biography slice groups name and biography Faculty entity subdivided into 4 slices The head slice is is general because it is representative of the slices. Links are reflecting navigation from general to more specific information. Link labels will offer preview insight into the purpose of the link and direct sensible anchor and link labels. General slice groups attributes name, description and rank Biography slice groups name and biography

15. Links between slices Interconnecting slices Labelling links �Structural links� = navigation between slices via uni and bi directional links of the same entity Traversal of associative link = information context changes -> global coherence or global navigation Traversal of structural link = information context remains with same entity -> local coherence or local navigation Labelled expertise in one direction and faculty in the other Unidirectional and bidirectional links specify access between slices Associative links are those in the ER diagramLabelled expertise in one direction and faculty in the other Unidirectional and bidirectional links specify access between slices Associative links are those in the ER diagram

16. M Slices Many web pages contain a collection of information from assorted "entities". m-Slices allow the modelling of presentation units which incorporate information from a collection of entities m-Slices can be nested Conventional RMDM only allows slices to be defined within a single entity The �m� refers to Russian Matrjeska dolls Conventional RMDM only allows slices to be defined within a single entity The �m� refers to Russian Matrjeska dolls

17. Web page m slice over collection of entities

18. ER model

19. M slice diagram The result is a SLICE DIAGRAM used in combination with the ER diagram (ER+) The result is a SLICE DIAGRAM used in combination with the ER diagram (ER+)

20. Design of the structures supporting navigation Each relationship appearing in the E-R+ diagram is analysed to determine whether it is appropriate If so it is replaced by one (or more) RMDM access primitives High level access structures group together items of interest menu-like access to the various material m-slice idea Designers have to identify the components and the way in which they are most likely to be accessed means that an understanding of the users and their context is typically quite important. Individual hard-coded links prohibited Additional primitives used to model application specific access structures E-R+ diagram is transformed into a final RMDM diagram (or application diagram, or both)  Steps 2 and 3 typically occur together in an iterative fashion.Additional primitives used to model application specific access structures E-R+ diagram is transformed into a final RMDM diagram (or application diagram, or both) Steps 2 and 3 typically occur together in an iterative fashion.

21. (Original) RMDM Access primitives Captures the navigational structure of a website / hypermedia application Uni-directional and Bi directional links specify access between slices of an entity Old RMDM supported navigation between entities Index � acts as a table of contents to a list of entity instances, providing direct access to each listed item. A guided tour implements a linear path through a collection of items, allowing the user to move either forward or backward on the path. circular guided tours links the last element back to the first with return to main menu has a distinguished node that contains information about the guided tour itself and is both the starting and end point of the guided tour with entrance and exit has different entrance and exit nodes Grouping construct is a menu-like mechanism that enables access to other parts of a hypermedia document � e.g. navigation maps, home pages. Indices are a special kind of grouping The conditions qualifying indices and guided tours determine which instances of an entity are accessible from the construct. Captures the navigational structure of a website / hypermedia application Uni-directional and Bi directional links specify access between slices of an entity Old RMDM supported navigation between entities Index � acts as a table of contents to a list of entity instances, providing direct access to each listed item. A guided tour implements a linear path through a collection of items, allowing the user to move either forward or backward on the path. circular guided tours links the last element back to the first with return to main menu has a distinguished node that contains information about the guided tour itself and is both the starting and end point of the guided tour with entrance and exit has different entrance and exit nodes Grouping construct is a menu-like mechanism that enables access to other parts of a hypermedia document � e.g. navigation maps, home pages. Indices are a special kind of grouping The conditions qualifying indices and guided tours determine which instances of an entity are accessible from the construct.

22. RMDM Access primitives Examples of the conditional RMDM access modelling primitives with conditions specified for each construct From RMM: A methodology for structured hypermedia design CACM 38:8 Aug 1995 Examples of the conditional RMDM access modelling primitives with conditions specified for each construct From RMM: A methodology for structured hypermedia design CACM 38:8 Aug 1995

23. RMDMdiagram Picture from CACM scanned in pg 37 The RMDM diagram describes, in addition to ER diagram, how users will navigate a hypermedia application. To avoid clutter, slices are not included in the figure above. Only the key attributes of entities are shown. Top of figure � grouping mechanism implements a main menu. Access into the faculty and course information is provided by guided tours. Access into programs is by an index. Choose the guided tour to the faculty entity, and the user can move back and forth among the faculty members (ordered alphabetically). From the faculty entity there is a conditional index into courses with predicate teaches (F,C). The reciprocal index taught_by(C,F) can be accessed from courses. Together these two indices represent a many-many relationship between faculty and courses. The teaches conditional index allows the user to move from the faculty entity to the courses taught by that faculty member. If there was an indexed guided tour for the courses taught by a faculty member, the user would be able to choose which course to visit first and from there, they could use the next and previous links to visit other courses taught by the same faculty member.Picture from CACM scanned in pg 37 The RMDM diagram describes, in addition to ER diagram, how users will navigate a hypermedia application. To avoid clutter, slices are not included in the figure above. Only the key attributes of entities are shown. Top of figure � grouping mechanism implements a main menu. Access into the faculty and course information is provided by guided tours. Access into programs is by an index. Choose the guided tour to the faculty entity, and the user can move back and forth among the faculty members (ordered alphabetically). From the faculty entity there is a conditional index into courses with predicate teaches (F,C). The reciprocal index taught_by(C,F) can be accessed from courses. Together these two indices represent a many-many relationship between faculty and courses. The teaches conditional index allows the user to move from the faculty entity to the courses taught by that faculty member. If there was an indexed guided tour for the courses taught by a faculty member, the user would be able to choose which course to visit first and from there, they could use the next and previous links to visit other courses taught by the same faculty member.

24. Replace ER+ relationship by access structure Conditional indexed guided tours implement the associative one-many relationship teach and taught_byConditional indexed guided tours implement the associative one-many relationship teach and taught_by

25. High level access structures The user of conditional access structures to provide access beyond that derived from associative relationships The two groupings implement a hierarchical menu-like access mechanismThe user of conditional access structures to provide access beyond that derived from associative relationships The two groupings implement a hierarchical menu-like access mechanism

26. RMDM Access primitives Experience has highlighted several problems. Unable to model certain types of structures presentation units where information from multiple entities is combined e.g. previous web page Solution -> m-slices Encourages explicitly top-down approach which isn�t always desirable Resource based reuse Solution -> Application diagrams Read: Hypermedia and the Web - pages 479-484 Read: Hypermedia and the Web - pages 479-484

27. RMDM diagram

28. Applica-tion Diagram Addresses (a) modelling presentation level information and (b) forced top-down approach The application diagram is aimed at explicitly showing the presentation units and the interconnections between these units, which go to make up the application. In the figure, each presentation unit corresponds to a HTML template which, when instantiated with data, will result in a specific web page. The star means that every other page has a link that connects to this unit In the navigation design, the presentation units to be included in the application diagram are identified by selecting all the m-slices which are the target of a link in the ER+ diagram, and then all links between these m-slices are also included into the application diagram. The outcome is thus not a RMDM diagram but an application diagram. The entity step (2) and the navigation step (3) are performed together. The result is bottom up, top down or combination. Addresses (a) modelling presentation level information and (b) forced top-down approach The application diagram is aimed at explicitly showing the presentation units and the interconnections between these units, which go to make up the application. In the figure, each presentation unit corresponds to a HTML template which, when instantiated with data, will result in a specific web page. The star means that every other page has a link that connects to this unit In the navigation design, the presentation units to be included in the application diagram are identified by selecting all the m-slices which are the target of a link in the ER+ diagram, and then all links between these m-slices are also included into the application diagram. The outcome is thus not a RMDM diagram but an application diagram. The entity step (2) and the navigation step (3) are performed together. The result is bottom up, top down or combination.

29. Merging entity and navigation steps Bottom up Designer initially focuses on each entity and then on the more general access mechanisms Top down Designer focuses first on the general structures during the slice design Converts these into lower-level presentation units In practice its iterative top-down and bottom-up Designer have to identify the components and the way they are most likely to be accessed Understand user and user context.

30. RMM design methodology Method focuses on design stages Process for creating a new application Requirements analysis Structural Design Stage 1: E-R Design Iterate around: Stage 3a: Navigation design (top-down) Design top-down application diagram Sketch, vision of application Break down each screen into components Stage 2: Slice Design: Design building blocks (m-slices) for components Stage 3b: Navigation design (bottom-up) Combine m-slices to generate bottom-up application diagram Compare application diagrams and refine / debug Stage 4: Conversion protocol design Stage 5: User interface design Stage 6: Run-time behaviour design Stage 7: Construction and Testing Requirements Analysis Various approaches: scenario analysis goal-based analysis workflow analysis Participation of users / stakeholders can provide requirements information Compilation of wish-lists Read: Hypermedia and the Web - pages 487-491 Method focuses on design stages Process for creating a new application Requirements analysis Structural Design Stage 1: E-R Design Iterate around: Stage 3a: Navigation design (top-down) Design top-down application diagram Sketch, vision of application Break down each screen into components Stage 2: Slice Design: Design building blocks (m-slices) for components Stage 3b: Navigation design (bottom-up) Combine m-slices to generate bottom-up application diagram Compare application diagrams and refine / debug Stage 4: Conversion protocol design Stage 5: User interface design Stage 6: Run-time behaviour design Stage 7: Construction and Testing Requirements Analysis Various approaches: scenario analysis goal-based analysis workflow analysis Participation of users / stakeholders can provide requirements information Compilation of wish-lists Read: Hypermedia and the Web - pages 487-491

31. Conversion and Interface Step 4: Conversion Protocol Design Develop a set of conversion rules Govern how to transform each element of the RMDM diagram into an appropriate object in the implementation environment Focuses on structural transformation Step 5: User Interface Design Each object in the final RMDM diagram is used as the basis for the design of suitable interface components Considers actual presentation - look-and-feel look of anchors, button layouts, positioning of video and images, etc

32. Final Steps Step 6: Run-time Behaviour Design Consider the functionality which supports the run-time behaviour. Includes: history lists link traversal possible inclusion of search engines dynamically generation vs static generation of pages etc. Step 7: Construction and Testing Application is actually constructed and evaluated

33. RM-CASE RM-CASE supports various �contexts� equating to the stages of development Supports "hyperbase population and simulation� Allows quick prototyping and evaluation Supports a very iterative approach to development Improves traceability within the development process Read: Hypermedia and the Web - pages 491-492 Read: Hypermedia and the Web - pages 491-492

34. Limitations and Strengths Strengths Relational model is well understood and supported Is not tied to a specific implementation Hypermedia model relates well to domain  Weaknesses Restricted to a specific class of applications Focuses on design and implementation phases of hypermedia product lifecycle Limited expressiveness (especially compared to OOHDM) Design not lifecycle method Good for regular non-volatile structure but volatile content Not good for irregular structured hypertext Separates domain model (ER) application structure model (slice + navigation design) application presentation model (conversion protocol, user interface design, runtime) But needs work on criteria, guidelines and specific details about how each phase should be done. Design not lifecycle method Good for regular non-volatile structure but volatile content Not good for irregular structured hypertext Separates domain model (ER) application structure model (slice + navigation design) application presentation model (conversion protocol, user interface design, runtime) But needs work on criteria, guidelines and specific details about how each phase should be done.

35. RMDM Remarks Effective Navigation and Browsing Cognitive Management during Browsing Information Contextualisation Link and Content Validity Information Structure Management of different media Application maintenance Reuse Supporting the full life cycle and process Cognitive Management during productivity Effective Navigation and Browsing creation of suitable application structure. RMM identifies and progressively refines the information space underlying the application. ER + groupings + indexing basing it on ER domain model provides consistent style of navigation and consistent look and feel � template based.Does explicitly address link traversal mechanisms, history mechanisms and search engines (but doesn�t tell you how). Cognitive Management during Browsing Use of image maps and consistent structure. Conversion protocol strategy assures consistent interface. Information Contextualisation differentiates between associative relationships between entities and links between slices within an entity. The former are semantic, the latter structural. Following the former changes context, following the latter doesn�t. Alerting a user to a change of context (different coloured links or background to presentation unit (web page). Or changing the window management for the different kinds of links. possible to see from which entity a given presentation unit (slice) is derived. E.g. a page is based on the author slice gives us the author context. sequence context � how info relates to other previously presented in a given sequence of access is not so supported. Guided tours are access structures not a mechanism for spec. or designing particular sequences of presentation. Link and Content Validity just having systematic design stages helps content validity based on ER so less likely to include spurious irrelevant information but doesn�t guarantee that its correct, just relevant. link validity ER ids the core associative relationships reflected directly in the final application. but lots of stages so (a) changes make designers reluctant to trace back to previous stages and tempts them to hackery and (b) there are a number of transformations that the design elements go through � reducing traceability and potentially introducing errors. Information Structure RMM Does not provide guidelines for the overall global structure of an application (hierarchical linear, breadth, depth etc). It develops an information structure by identifying inherent relationships amongst the information. The final structure emerges from the related design stages. (a) chunk your nodes Slicing up the information units into presentation units � but RMM doesn�t really give good guidance on what makes a good slice. M-slices are not limited to one entity and thus run the danger of producing slices that are not cohesive. (b) link your chunks Presentation unit linking. ER design ids core associative relationships but RMM doesn�t id suitable links. Number of structural building blocks in RMM is small � either single links or one of a small set of access structures. Management of different media doesn�t help. Attributes of entities can be any type, but no help for synchronisation, combinations, or contextual link following with other media. Application maintenance does help though no explicit stage. Aimed at volatile structured applications � volatile content not structure. Just having the stages with different documented and traceable deliverables helps maintenance. separates domain knowledge, application structure and implementation. � data independence supports change. App structure is independent of presentation environment. change in content reduces to adding content to a database � templates already in place. Reuse different deliverables are reusable (e.g ER) m-slice � captures info about presentation units that can be reused and promotes combined top down and bottom up design of application structures. So low-level structures already around can be identified and reused. Supporting the full life cycle and process it doesn�t � it should be used in conjunction with one. Its top down so combining with rapid prototyping might be hard. Cognitive Management during productivity provides a specific set of steps to help the developer. - developer has a roadmap - developer focuses on important aspects at appropriate points - set of tools and techniques help - consistent terminology and notation minimises ambiguity and confusion.Effective Navigation and Browsing creation of suitable application structure. RMM identifies and progressively refines the information space underlying the application. ER + groupings + indexing basing it on ER domain model provides consistent style of navigation and consistent look and feel � template based.Does explicitly address link traversal mechanisms, history mechanisms and search engines (but doesn�t tell you how). Cognitive Management during Browsing Use of image maps and consistent structure. Conversion protocol strategy assures consistent interface. Information Contextualisation differentiates between associative relationships between entities and links between slices within an entity. The former are semantic, the latter structural. Following the former changes context, following the latter doesn�t. Alerting a user to a change of context (different coloured links or background to presentation unit (web page). Or changing the window management for the different kinds of links. possible to see from which entity a given presentation unit (slice) is derived. E.g. a page is based on the author slice gives us the author context. sequence context � how info relates to other previously presented in a given sequence of access is not so supported. Guided tours are access structures not a mechanism for spec. or designing particular sequences of presentation. Link and Content Validity just having systematic design stages helps content validity based on ER so less likely to include spurious irrelevant information but doesn�t guarantee that its correct, just relevant. link validity ER ids the core associative relationships reflected directly in the final application. but lots of stages so (a) changes make designers reluctant to trace back to previous stages and tempts them to hackery and (b) there are a number of transformations that the design elements go through � reducing traceability and potentially introducing errors. Information Structure RMM Does not provide guidelines for the overall global structure of an application (hierarchical linear, breadth, depth etc). It develops an information structure by identifying inherent relationships amongst the information. The final structure emerges from the related design stages. (a) chunk your nodes Slicing up the information units into presentation units � but RMM doesn�t really give good guidance on what makes a good slice. M-slices are not limited to one entity and thus run the danger of producing slices that are not cohesive. (b) link your chunks Presentation unit linking. ER design ids core associative relationships but RMM doesn�t id suitable links. Number of structural building blocks in RMM is small � either single links or one of a small set of access structures. Management of different media doesn�t help. Attributes of entities can be any type, but no help for synchronisation, combinations, or contextual link following with other media. Application maintenance does help though no explicit stage. Aimed at volatile structured applications � volatile content not structure. Just having the stages with different documented and traceable deliverables helps maintenance. separates domain knowledge, application structure and implementation. � data independence supports change. App structure is independent of presentation environment. change in content reduces to adding content to a database � templates already in place. Reuse different deliverables are reusable (e.g ER) m-slice � captures info about presentation units that can be reused and promotes combined top down and bottom up design of application structures. So low-level structures already around can be identified and reused. Supporting the full life cycle and process it doesn�t � it should be used in conjunction with one. Its top down so combining with rapid prototyping might be hard. Cognitive Management during productivity provides a specific set of steps to help the developer. - developer has a roadmap - developer focuses on important aspects at appropriate points - set of tools and techniques help - consistent terminology and notation minimises ambiguity and confusion.

36. Further Reading HDM: Garzotto, Mainetti and Paolini. Hypermedia Application design: A structured approach. In Designing User Interfaces for Hypermedia Springer Verlay (1995) RMM: Isakowitz, Stohr and Balasubramanian RMM: A methodology for Structured Hypermedia Design CACM vol 38, no 8 (Aug 1995) OOHDM: Schwabe, Esmeraldo, Rossi, Lyardet Engineering Web Applications for Reuse in IEEE Multimedia vol 8 no 1 (Jan-Mar 2001) pdf Schwabe and Rossi An Object Oriented Approach to Web-Based Application Design in TAPOS pdf German and Cowan Towards a unified catalog of hypermedia design patterns in Proceedings of the 33rd Hawaii International Conference on System Sciences � 2000 pdf Perzel and Kane Title: Usability Patterns for Applications on the World Wide Web in PloP �99 Conference. pdf

37. Further Reading Bernstein�s hypertext patterns http://www.eastgate.com/patterns/Print.html Hypermedia Design Patterns Repository http://www.designpattern.lu.unisi.ch/HypermediaHomePage.htm Hypermedia Development Workshop Series http://www.eng.uts.edu.au/~dbl/HypDev/ General Web Resource: Webmonkey http://hotwired.lycos.com/webmonkey/