Visual Semantic Modeling of Digital Libraries

Qinwei Zhu, Marcos André Gonçalves, Rao Shen, Edward A. Fox – Virginia Tech, , Blacksburg, VA, USA Lillian Cassel – Villanova University, PA, USA

Acknowledgements NSF Grants

CITIDEL: DUE-0121679 DL-in-a-box: DUE-0136690 ETANA: ITR-0325579 GetSmart: DUE-0121741 OAD: IIS-0086227

Others AOL Capes (Brazilian funding agency)

Outline Motivation The 5S Family: model, language,

generation The 5SGraph Modeling Tool Evaluation Semantic Modeling of DLs with Concept

Maps Conclusion

Motivation DLs are not benefiting from formal theories

as have other CS fields: DB, IR, PL, etc. DL construction: difficult, ad-hoc, lacking

support for tailoring/customization Conceptual modeling, requirements analysis,

and methodological approaches are rarely supported in DL development. Lack of specific DL models, formalisms,

languages

5S model/ 5S languageModel Formal definition Objective within 5SL

Streams Sequences of arbitrary types Describe properties of the DL content such as encoding and language for textual material or particular forms of multimedia data

Structures Labeled directed graphs Specify organizational aspects of the DL (e.g., structural /descriptive metadata, hypertexts, taxonomies, classification schemes)

Spaces Sets of objects and operations on those objects that obey specific constraints

Define logical and presentational views of several components.

Scenarios Sequences of events that modify states of a computation in order to accomplish some functional requirement

Detail the behavior of the DL services

Societies Sets of communities and relationships (relations) among them

Define managers, responsible for running DL services; actors, that use those services; and relationships

5SL primitives and implementationModel Primitives 5SL implementation

Streams Model

Text; video; audio; picture; software program MIME types

StructuresModel

Collection; catalog; hypertext; document; metadata; organization tools

XML and RDF schemas; Topic maps ML (XTM)

SpacesModel

User interface; index; retrieval model MathML, UIML, XSL

ScenariosModel

Service; event; condition; action Extended UML sequence diagrams; XML serialization

SocietiesModel

Community; service managers; actors; relationships; attributes; operations

XML serialization

5S DL generation

5S Meta

Model5SLGraph

DL Expert

DL Designer

5SL DL

Model

5SLGen

Practitioner

Researcher

TailoredDL

Services

Teacher

componentpool

ODLSearch,ODLBrowse,ODLRate,ODLReview,

…….

Requirements (1) Analysis (2)

Implementation (4)

Design (3)

Challenges with Approach The designer should know the 5S theory

very well and be very familiar with the syntax and semantics of 5SL to be able to write correct 5SL files.

It is difficult to get the big picture of a digital library just from a textual 5SL file.

Overall objective of 5SGraph:Help users model their own instances of a digital library (DL) in the 5S language (5SL).

A simple modeling process which enables rapid generation of digital libraries is needed.

Support non-expert users. Speed-up development process. Increase the quality of final product.

5SGraph: A DL Modeling Tool

Goals of 5SGraph To help digital library designers understand the

5S model quickly and easily To help digital library designers build their own

digital libraries without difficulty To help digital library designers transform their

models into 5SL files automatically To help digital library designers understand,

maintain, and upgrade existing digital library models conveniently

5SGraphHow does 5SGraph work?

5SGraph loads and displays a metamodel in a structured toolbox.

The structured editor of 5SGraph provides a top-down visual environment for the DL designer.

5SGraph produces correct 5SL files according to the visual model built by the designer.

Overview of 5SGraph

Workspace

(instance model)

Structured

toolbox

(metamodel)

Visualization Features The structured toolbox

Visualization of the metamodel Visual components that can be added

Truncated display of trees Node-link representation Deep-node problem

Icons Type/Instance relationship

Cardinality

Component Reuse Components can be loaded/saved.

Load and save sub-trees Component reuse saves time and effort.

Full reuse from component pool Partial reuse: adapting components

Semantic Constraints• There are inherent semantic constraints in the

hierarchical structure of the 5S model.

• 5SGraph maintains the constraints and enforces these constraints over the instance model to ensure correctness.

Example 1 (Constraint Enforcement) An actor can only participate in the

services that have been defined in the Scenario Model.

Example 2 (Constraint Enforcement) A catalog has descriptive metadata for

digital objects in a specific collection. Therefore, a catalog must have a 1:1

relationship with an existing collection. Thus, a catalog is not independent.

The Preliminary Test of 5SGraph Research Questions

Does the tool help users understand and use the 5S model to build their own digital libraries?

Does the tool help users efficiently describe digital library models in the 5SL language?

Are users satisfied with the tool?

The Preliminary Test of 5SGraph: Experimental Design

Three tasks1. Build a simple digital library using existing components.2. Complete the partial model for CITIDEL.3. Build a model for NDLTD from scratch.

Three measures Effectiveness Efficiency User satisfaction

17 subjects

Measures Effectiveness

Completion rate Goal achievement

Efficiency Task completion time Closeness to expertise: minimum task time divided by

task time Satisfaction

Subjective rating

Test Results  Task 1 Task 2 Task 3

Completion Rate (%)

100 100 100

Mean Task Time (min)

11.3 11.4 15.1

Mean Closeness to Expertise

0.483 0.752 0.712

Mean Goal Achievement (%)

97.4 97.4 98.2

Satisfaction and Usefulness The average rating of user satisfaction is 91%.

The average rating of usefulness of the tool is 92%.

Statistical analysis shows that the mean value of post-understanding of the 5S model is significantly greater than that of pre-understanding.

Educational UseUnderstanding of 5S Theory

0.0

2.0

4.0

6.0

8.0

10.0

Pre Post

Semantic Modeling of Digital Library with Concept Maps Customized “plugin” tool to model

scenarios and societies Tools with common principles,

abstractions, graphical notations, and operations

Solution: Concepts Maps Conceptual tools for organizing knowledge

and representation

Conclusions Presented a domain specific visual

modeling tool for DLs. Evaluated the tool and proved efficiency,

effectiveness, and learnability. Built new tools based on concept maps for

scenario and societies modeling.

Future work Integration of tools Further usability studies with “digital

librarians” Usiing the tools as educational aids for

teaching about digital libraries

Learnability

0

0.10.2

0.30.4

0.5

0.60.7

0.80.9

1

1 3 5 7 9 11 13 15 17Task1Task2Task3