elearning Content Management Middleware

Transcription

1 elearning Content Management Middleware Chen Zhao Helsinki University of Helsinki Department of Computer Science

2 Authors Chen Zhao Title elearning Content Management Middleware Date Pages 12 pages Abstract Content Management System (CMS) Middleware provides a bundle of tools for educational content creation, management and delivery. We introduce one of the CMS middleware named as ecms. ecms is a web-based CMS middleware which supports features like metadata repository, course / examination creation, modification and publication, statistics collection and analysis. ecms implements a 3-tier architecture with the possibility to build a distributed ecms network at the server end. ACM Computing Classification System ( CCS, 1998 ) A.1 [Introductory and Survey] Keywords elearning, content management, middleware, courseware, content reuse

3 Content 1. Introduction ecms functional model ecms architecture and components Metadata Course Developer and Editor Examination Developer and Editor System Statistics Additional ecms services Conclusions...9 References...9

4 1. Introduction A Content Management System (CMS) is a combination of tools that enables content providers to create, maintain, store, reuse and finally publish the digital content in various formats (such as text, graphics, video etc). The system should be able to separate the content from its presentation to allow the non-technical users to create and manage the content directly while being constrained by a centralised set of rules, processes and workflows that ensure a coherent, validated course quality. As a system tool that emphasizes on managing processes of creating and publishing learning content, CMS has several common features including but not limited to: content assembly tools, content authoring tools, content version control, templatebased publishing tools, workflow process management, metadata features such as metadata enabled content repository. Content Management Middleware refers to web-based CMS, centralized or decentralized. With a centralized model, content is managed in a centralized place for increased control and security. With a decentralized model, content is stored in different locations, which are connected via Internet. Decentralization is usually transparent to users such as content providers, course managers and learners. Since content is connected for federated searching and managing, users do not need to know where content is physically located. There are many Content Management Middleware vendors in the market. In this paper, we introduce one of those products named as ecms (elearning Content Management Middleware) developed under MINERVA-SOCRATES funded project CP GR-MINERVA-M Content Management Middleware for the support of elearning across Europe [TSBC2001]. The rest of the paper is organized as follows. In Chapter 2 we introduce the ecms functional model. In Chapter 3, we explain in details about ecms architecture and its components. In Chapter 4 comes 1

5 out the additional services and functions provided by ecms. And finally we present a brief summary of ecms and the possible future work. 2. ecms functional model ecms provides an web-based, open, distributed middleware for federated content management. Its functions include creation, reuse, management, publication, discovery, retrieval and integration of educational content. ecms users include learners, content providers, course managers and repository administrators. Public service Learners Metadata Provider Service Content Providers Content Manager Service Course managers System statistics. Administrator. Service Administrator Server side Middle tier (Application server) Client side Figure 1. ecms functional model Figure 1 displays the functional model of ecms. It is a 3-tier implementation. The server side deploys databases to store the metadata, content and system statistics. ecms support distributed implementation from the server side. This means ecms can 2

6 be either a single independent instance or a decentralized system by joining more ecms nodes to form a wider ecms network. Each node stores its own metadata and content and support queries from other nodes. Decentralized ecms network is implemented thought the metadata synchronization and distributed query functions. In a decentralized ecms network, each participating organization can enjoy the scalability of metadata and content volume while still maintains the autonomy in the content management within its own node. Organizations can easily join into or detach from the ecms network at their convenience. The middle tier deploys come commercial Application Servers to implement the business logic. It provides services and interfaces for each user groups in the ecms system. Public service is for learners, which includes metadata search, content navigation, content review, participation in course examinations, learner profile management and basic collaboration such as learner forums and chat rooms. Please note that some of the services for learners belong to the Learning Management System (LMS). However, ecms does cover those features while emphasizes on the content management and delivery. Provider service is for content providers, which includes content hosting (optional), course module development, management and publication, metadata generation and workflow management. Manager service is for course managers to edit, schedule or publish course modules, manage examinations and access course reviews. Administrator service is for the ecms repository administrators to manage the user accounts and groups, gather and analyse system statistics such as information on course operations, synchronize metadata repositories to support distributed queries in a ecms network. We introduce only ecms tools and functions related to content management in this paper, hence system administration and maintenance are not mentioned here. All the user interfaces reside on the client side. ecms offers separate user interfaces for learners, content provides, course managers and repository administrators. The system requirements are minimized on the client side because of the 3-tier implementation with modularity of services. As shown in the ecms functional model, 3

7 powerful and scalable application servers are essential for the high availability for the end users, high performance in interoperability among the ecms components and security for distributed user and content management. 3. ecms architecture and components The main components of ecms system are metadata store, optional content hosting area, statistics store and publication service tools such as course developer and editor, examination developer and editor. 3.1 Metadata Educational content metadata plays one of the most import roles in ecms. It keeps descriptive records for publishers, content modules, users, and optional repositories in other ecms nodes. It allows content modules to be stored, reused, managed and retrieved in an efficient way for authorized users. Metadata Publishers Security info. Thematic area Indexes Ref to cntent, indexes Modules Ref Repository content directory Figure 2. ecms Educational Content Metadata 4

8 Figure 2 shows all the information that is recorded in the metadata. All those are stored in relational database tables. There are tables maintaining the hierarchy information on publishers and their institutions. Thus Metadata search based on publishers is supported based on this information. Metadata search and navigation is also supported based on the thematic information. Tables of content modules contain information on module type, status and hierarchy structure for each module. Module type can be courses, chapters or sections, etc. It enables the flexible course structures as adding a module at any level is dynamic and simply. We talk about the flexible course structures in more details in the section 3.2. Module status shows the module s availability, such as ready for publication, for internal review or available for reuse. Module hierarchy records the relationships among modules. Security information as user accounts and access records is held in the metadata to enforce user identification and authorization. Metadata contains references to the content modules and there are text-based indexes build on the content to support free text searches. Optionally, metadata maintains a directory of all the available repositories in an ecms learning network. The directory is build during the metadata synchronization mentioned in Chapter Course Developer and Editor ecms Course Developer and Course Editor are the structured-course authoring tools. Course Developer is used for creation of structured courses while Course Editor is for reviewing and modifying the existing courses. 5

9 Course Developer guides authorized content providers to construct courses in four steps. First, the tool asks content providers to submit course metadata descriptions such as course name and instructor names, search keywords, content classifications, etc. Then, providers can add modules to the course. The submitted module can be either a new entity or a reused one. If a new entity, the tool will request provider to submit module descriptions to the metadata store. Next, providers are able to attach the content to the module. Content may physically be uploaded to the ecms content hosting area or it can be a URL to the remote content. At last, the module hierarchy is maintained and recorded in the module hierarchy table in the metadata. Figure 3 shows how Course Developer works with the Metadata. login Metadata Course Developer (Course Editor) metadata submisstion Publisher info., thrmatic info., ref. to content, module info. Figure 3. Course Developer / Editor and Metadata Course Editor is used to review the existing courses and modify the content, modules, or module hierarchy as needed. It supports operations as editing course metadata descriptions, modifying content and attaching/detaching content to modules, publishing or hiding or deleting course modules. Content providers can use Course Editor to easily change the course module hierarchy by adding or deleting course modules dynamically. Course modules at any level can be modified and the new hierarchy information is recorded into the metadata. The module hierarchy approach ensures maximum flexibility in course structures. 6

10 3.3 Examination Developer and Editor ECMS Examination Developer and Examination Editor are the authoring tools for course managers to create and manage multiple-choice self-assessment examinations for learners. The examinations can be created as standalone or to be associated with the courses, or to be associated to certain courses after the creation. Examination Developer deploys the similar top-down construction approach in examination creations as the Course Developer in course creations. First, Examination Developer requires the general metadata description for the new examination. It also let the course managers to decide if the examination should be linked to some course or not. Next, managers are guided to add multiple-choice questions to the examinations. After the creation, managers may use Examination Editor to review the whole examination, modify its metadata, add or delete questions. Just as the ecms Course Developer and Editor, Examination Developer and Editor adopt the module approach to ensure the flexible examination structure. 3.4 System Statistics System statistics is important for repository administers to get information on ecms system usage and improve the services based on that information. ecms divides System Statistics Store into two parts: the Raw Statistics area and the Analysed Statistics area. ecms collects and analyses the system statistics without the administrators interference. ecms collects and stores unprocessed information on users, metadata searches and content module usages in the Raw Statistics area. The raw information is then analysed and the results are saved to the Analysed Statistics area. Analysed statistics are interpreted information in an easy- understood format for administrators review. Such analysed statistics includes occurrence of a particular keyword in metadata searches, ecms identifiers of matched records, and reviewed metadata entities, etc. Those statistics give administrators a detailed picture of how exactly the ecms 7

11 services are utilized and a base point of what to improve with respect to the metadata and content. 4. Additional ecms services In Chapter 2 we review the ecms functional model with ecms services for all the parties involved in the system. In Chapter 3 we present the main services provided by ecms tools, which are the course management service by Course Developer and Editor, examination management by Examination Developer and Editor, and statistics collection and analysis by System Statistics Store. Metadata Store provides various search and navigation services and its management service is integrated in Course/ Examination Developer and Editor tools. Besides those main services, there are several additional services provided by ecms. For learners, ecms provides Learner Profile management service to record and manage personal account information. ecms also provides a basic collaboration environment which includes chat-rooms, forums and application sharing. Learners can also submit course reviews and ratings online and give general feedback via s. ecms provides workflow management for content providers and course managers. Other service for content providers and course managers is to access content reviews and ratings. For repository administrators, ecms provides the ways to synchronize the metadata repositories and enable the metadata caching in a distributed ecms network environment. Metadata synchronization support distributed queries and metadata caching will further speed up the distributed queries. ecms supports integration of external repositories to ecms repositories to some extent. Repository administrators may invoke the metadata importing function to 8

12 migrate the non-ecms repositories to ecms system. This service may need administrators interference in defining the external repository format in order to map it to the ecms repository format. 5. Conclusions We present the ecms components and all its functions and services in this paper. ecms is a scalable CMS for management and publication of the educational content. It separates the content from the presentation and provides wizard-based tools to facilitate non-technical users to create, manage and publish the content. The scalability of ecms is achieved by joining ecms nodes together to form a wider learning network. In an ecms learning network, each participating party enjoys the increased volume of metadata and content while keeping the autonomy its own node management. Distributed information discovery in an ecms network is supported by the metadata synchronization and benefits more from the metadata caching. ecms already includes the possibility to migrate other existing metadata repositories to the ecms repository. However, the integration and interoperation between ecms and other CMSs and LMSs (Learning Management System) remains a future work for the ecms development. References [TSBC2001] ecms (2001): Content Management Middleware for the support of elearning across Europe, MINERVA-SOCRATES funded project CP GR-MINERVA-M, ecms: elearning Content Management Middleware Harkilia Tsalapatas, John B.Stav, Paul Brna, Christos Calantzis 9