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5. Case Study: Networks Design Course

5.1 Objectives of the case study

In this chapter, we will go through the complete process of designing a course for distributed open learning. This course will then be implemented using Lotus LearningSpace. As discussed in section Groupware and Combining groupware and WWW, Lotus LearningSpace is one example of groupware-based DOLE. This category of DOLE is supposed have several advantages over Internet applications-based DOLE.

Since the main purpose of this project is examining DOLE, the evaluation done will be limited to Lotus LearningSpace. The course itself will not be evaluated in depth, as it was never delivered to real learners. However, we believe the process of designing a distributed open learning course is important to standardisation efforts, so it will be done methodically.

5.2 Course Description

Summary

This advanced course is intended provide guidelines and methodology in designing computer networks, specifically local area networks (LAN). As no single network will fit all purpose, the course will be based on case studies, and aim at maintainable network designs. The learners will be expected to work in teams. Each team will consist of several roles such as hardware engineer, protocol specialist, application analyst, etc., played by the learner. The target learner for this course is assumed to be familiar with the basics of computer networks and internetworking. The duration of the course is three days when done full-time and two weeks when done part-time.

Aims

The aims of this course are:

Objectives

By the end of this course, the learner should:

Course Outline

The content of the course is adapted from (Charles, 1997) and (Smythe, 1995, chap. 15). In developing it we use a hypertext instructional design methodology from (Mengel & Adams, 1996). It is particularly appropriate for this course since it will be implemented in Lotus LearningSpace as a hypermedia document. Indeed, as most DOLE are based on hypermedia documents, it would seem that choosing a common methodology when designing courses is an important step towards standardisation of DOLE. The steps of the methodology are as follows:

  1. State the thesis of the course in a single sentence.
  2. Expand the sentence into a high level paragraph.
  3. Identify key concepts.
  4. Identify key relationships between key concepts and the paragraph theme.
  5. Review and revise.
  6. For each new concept, repeat steps 1-5 as needed.
  7. Encapsulate related concepts in a single-object module.
  8. Implement text links in hypertext.

5.3 Requirements stage

At this stage we focus on determining the scope of the course.

Thesis sentence of the network design course

Following these steps, we first state the thesis sentence of the network design course:

Network design is the process of designing and implementing LANs using components that provides the users with the necessary level of service and high maintainability.

The corresponding expanded paragraph of the above statement is:

Network design is the process of designing and implementing LANs using components that provides the users with the necessary level of service and high maintainability. LAN components are chosen based on evaluating their specification against the required criterias. Providing service means the users are getting what they need. High maintainability can be achieved by specifying and documenting the LAN.

From the expanded paragrah we can extract the key concepts:

For each of these concepts, we will repeat steps 1-5.

Concept 1: Choosing LAN components

The thesis sentence for the concept of choosing LAN components is:

Choosing LAN components is the process of assessing and evaluating commercial-off-the-shelf (COTS) products.

The corresponding expanded paragraph of the above statement is:

Choosing LAN components is the process of assessing and evaluating commercial-off-the-shelf (COTS) products. The LAN components that needs to be evaluated include:

From the above paragraph we extract the eight component categories listed, and make each category a separate topic. As the topics are specific enough, we do not need to decompose further.

Concept 2: Providing necessary level of service

The thesis sentence for the concept of providing necessary level of service is:

To provide the level of service required, a requirements analysis needs to be done. This involves gathering from the user three kinds of requirements: functional, operational, and performance requirements.

The corresponding expanded paragraph of the above statement is:

A requirements analysis involves gathering from the user three kinds of requirements: functional, operational, and performance requirements. Gathering functional requirements means finding out the set of LAN functions needed to support user activities. This consists of physical (such as cabling) and logical (such as office automation) functions. Gathering operational requirements means finding out how to operate the network. This includes management, security, and recovery aspects. Gathering performance requirements means finding out the operating parameters needed from the LAN. For example, parameters such as throughput, number of users, and expected data storage must be determined.

The key concepts extracted from the above paragraph are:

Since these topics are specific enough, we will not decompose them further.

Concept 3: Specifying and documenting

The thesis sentence for the concept of specifying and documenting is:

Documenting the design and implementation process is an essential step towards high maintainability.

The corresponding expanded paragraph of the above statement is:

Documenting the design and implementation process covers creating, refining, and formalising the following deliverables:
  1. Configuration management plan
  2. Quality assurance and test plan
  3. Training plan
  4. LAN transition plan
  5. System operations and configuration manual
  6. User's manual

The concept of producing the above deliverables are specific enough, and need not be decomposed further.

Concept linking

All of the above concepts can now be linked together, as shown in Figure OOTD. This diagram is called an object-oriented text decomposition (OOTD) graph. The OOTD graph will be refined further in the next stage, the specifications stage.

OOTD graph for the networks design course

5.4 Specifications stage

In this stage, the OOTD graph will be refined to make it suitable for hypertext format. The steps in this stage are:

  1. Classify links in the graph as first-order or second-order. First-order links are the path which a learner must follow in order to understand the course. Second-order links are there to connect related concepts, and assist the learner during the course.
  2. Identify key concepts.
  3. Concepts are grouped together according to their instructional theme. This grouping structures related concept close together, resulting in continuity to the learner.

Figure Concept map shows the results of the refinement steps above. There is one concept grouping, for the requirements gathering concept. The three concept from the first decomposition are identified as key concepts, and their links from the main concept are first-order links. This map may be refined further with additional notes to allow for instructional and administrative issues or used as it is.

Concept map for the networks design course

5.5 Collaborative Activities

The hypertext instructional design methodology used above covers designing course materials from scratch, and resulted in graphs suitable for implementation in DOLE. However, the methodology does not cover designing collaborative activities, one important requirement for DOLE.

For the networks design course learners will work in teams. Each team will be given a scenario, and will be required to deliver a complete networks design specification at the end od the course. Collaboration among members of a team is important, because the required design specification will be too large for a single learner or even several uncoordinated learners.

5.6 Implementation in LearningSpace

The course above was implemented in a beta version of Lotus LearningSpace. The features are similar with release 1.0. Currently Lotus is already shipping release 2.0. This release has additional features, most notably allowing WWW access for learners.

All interaction with Lotus LearningSpace is done through Lotus Notes Client software. This software is a proprietary product that needs about 30 Megabytes of hard disk space for a typical installation.

Implementing a distributed open learning course in Lotus LearningSpace involves setting up at least the four main modules: Schedule, CourseRoom, MediaCenter, Profiles. If required, the Assessment module may also need setting up. To illustrate the implementation of the networks design course, we will look at the process from several point of views:

These point of views corresponds to some of the roles in DOLE we specified earlier in section Enterprise Specification. For each role, we will look at how they used Lotus LearningSpace to implement the course.

Course Content Author

Schedule

The first thing to do is setting up the Schedule module, as this module is the controlling module of other modules. It is also the starting point for learners. The steps outlined below will shows a typical path of setting up Schedule:

  1. Course setup. This involves naming the course, giving a description, and setting the paths to the other modules. The course can be organised in several ways, such as per unit or per day. The networks design course is organised as consisting of several days.
  2. Adding schedule entries. Schedule entries are in divisions as specified in the course setup (units, days, etc.). A schedule entry can contain links to CourseRoom or MediaCenter.

CourseRoom

The CourseRoom

is setup by creating the initial discussion forums.

MediaCenter

Since this module is the repository for all information relevant to the course, the main learning material is stored here.

Profiles

Course Instructor

Course instructors will mainly use the CourseRoom to interact with learners.

Learner

Learners will start at the Schedule module, and can see the outline according to the division chosen by the content author.

Learner Assessor

The learner assessor will be responsible for setting up the Assessment module.

5.7 Evaluation of Lotus LearningSpace

Since the network design course was never actually delivered to learners, this evaluation is rather limited. Issues such as managing learners, scalability, and learner participation could not be evaluated. However, we can still evaluate the process of setting up the course. The evaluation will also be limited to the usage of Lotus LearningSpace, not the installation of LearningSpace software itself. It is assumed that LearningSpace is already installed, and ready to accessed and customised.

Hardware and software requirements

The main software requirement to access LearningSpace is the installation of Lotus Notes Client, which in the 16-bit Microsoft Windows version needed at least 40 MB of hard disk space for a typical installation. A full installation would need 70 MB of hard disk space. The minimum memory requirement of this client software is about 8 MB of RAM. Even then, during the implementation of the networks design course, there are occasions when the client software complained of lack of memory. So a comfortable working environment would need at least 16 MB of RAM.

Connection to a network is also essential, either directly on a LAN connected to the Lotus LearningSpace server or remotely through remote networks such as the Internet. The case study was implemented using the latter method. A PC was configured to access the Internet, and the Lotus Notes Client was set up connect the server using TCP/IP over the Internet.

Groupware facilities

Since Lotus LearningSpace uses Lotus Notes (an established groupware platform), it has excellent support for replication and asynchronous collaboration.

Replication

Replication is the differentiating feature with other model of DOLE, especially WWW-based ones. Nomadic learner can connect once to replicate the modules. After that the replication facility will only synchronise the changes. This greatly minimises connection time, and in turn minimises cost to learners. However, it should be noted that the databases are large, averaging 2 MB each. Accessing LearningSpace through the Internet, using standard dial-up facilities, it took almost an hour to complete the initial replication.

Asynchronous collaborative activities

Facilities for managing and participating in discussion forums are excellent. Together with the replication facility, nomadic learners can participate in discussion forums off-line and synchronise when connected.

Conformance to standards

Strictly speaking, there are no standards as yet, so we could not say precisely whether Lotus LearningSpace conforms to any DOLE standards. However, as discussed in chapter 2, emerging trends and requirements of DOLE can already be identified.

One missing feature is synchronous communication facilities. Although successful distributed open learning can be done using asynchronous communication, this feature is desirable for a comprehensive DOLE.

WWW facilities

For better access, it is desirable to combine WWW with groupware (as discussed in section Combining groupware and WWW). This is not available in the version used in this project. However, the current release allows learners to access Lotus LearningSpace using an ordinary WWW browsers. Course instructors and contetn authors still have to use the proprietary Lotus Notes client software.


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