Introducing the Virtual Campus project
Virtual Campus objectives
The Polimi Virtual Campus platform is an open system for the design,
deployment, fruition, and evaluation of reusable learning materials.
Its main objectives are:
- To support design, composition, and reuse of Learning Objects
- To support fruition of Learning Objects:
- Traditional and ad-hoc settings.
- Personal and cooperative usage.
- To support analysis of students' behavior (learning, relational,
and normative aspects).
- To analyze power consumption in all envisaged scenario.
- To experiment the usage of our learning platform and of advanced
learning objects in our CS courses.
- Development of a conceptual model that extends the IEEE LOM.
- A prototype that integrates various competences (software engineering,
database, hypermedia, hardware design).
- Usage of innovative and consolidated technologies from MS and
Politecnico di Milano.
Reusability of learning materials is key in order to improve the
cost-effectiveness of computer aided learning environments. Thus,
learning materials in Virtual Campus take the format of "learning
objects" (LOs) of arbitrary complexity, typically arranged into
hierarchies of smaller granularity LOs, described by a meta-model.
A semantically rich description of LOs is useful for understanding
their features and for enabling their publishing in a Web context.
The richness of LO metadata structure enables their reuse across
completely different learning sessions, by improving search capabilities
and by providing information supporting intelligent retrieve.
A LO is defined as the smallest unit that can be delivered into
the Virtual Campus. It is the smallest unit that can be assigned
to a leaner and for which a learner’s position may be traced.
Structurally a LO is composed by a metadata part and a
In the Virtual Campus model everything is classified in terms of
LOs. The concepts of “class”, “exam”, “course”
do not exist in themselves, and are modeled as LOs. Single LO can
be aggregated into more complex learning units (in their turn defined
in terms of LOs) through the use of “relationships”.
The figure below shows LOs and their relationships.
LOs and their relationships
A system for managing LOs should represent them at three different
abstraction levels: the reusable-content level, where LOs content
is defined in a way to be applicable to multiple contexts; the didactic
level, where LOs are seen in the context of a specific didactic
use, e.g. a given university curriculum; and the fruition level,
where the actual embodiment of a virtual class is defined, by describing
the class milestones, the actors participating to the class and
their roles relative to LOs, and so on. The design support system
should be suitable for the interaction with "content providers"
covering three different roles of author, course organizer, and
teacher; each role is involved with the relevant level of the specification.
Learning processes defined by complex learning objects need to be
supported by the system engine. Under this viewpoint the system
acts as workflow environment: it manages learning and working data,
producing proper outputs that are distributed again to users, in
order to support their activities and improve their work efficiency.
Virtual Campus architecure and models
High level architecture
The Virtual Campus platform is composed of an Authoring Environment
and a Fruition Environment. The authoring environment allows users
to create and manage LOs at the three levels defined in the previous
section. The fruition environment provides all mechanisms to exploit
LOs for the purpose of providing and obtaining an educational service.
The core of the fruition environment is an engine that executes
the fruition process defined as a part of LOs. The evaluation environment
constantly monitors and collects metrics on the effectiveness of
LOs and on the behavior of learners and teachers. All such data
provide useful feedbacks that are then used to improve LOs. The
figures below provide a view on the architecture.
Virtual Campus Authoring Environment
The three-level model
The Virtual Campus design is expected to maximize
re-use (allowing Authors/Organizers to easily modify and assemble
LOs) and customisation (allowing Learners to adapt fruition to their
personal preferences) of the Learning Objects. In order to achieve
these goals, the LO “life-cycle” has been divided into
three different phases (or "levels").
Reusable-content Level (RL)
Our strategy is to express CLOs without making use
of explicit paths definition. In other words, we’ll use a
language that gives Organizers the opportunity to express logic
dependencies among LOs (i.e. “knowledge about Limits is required
in order to understand Derivatives”, “Analysis3 and
Calculus are alternative so Learners can choose either the former
or the latter”, etc).
Notice that, using such language, Organizers don’t impose
an a priori ordering to LO fruition, limiting themselves
to the definition of the constraints a given path must respect.
Therefore, Organizers can focus on didactical relationships among
LOs (what pieces of knowledge a student must learn in order to understand
a given LO, whether diverse LOs give the same knowledge, whether
a piece of knowledge is compulsory or represents an optional didactical
Didactical Level (DL)
In DL, we make use of a “workflow-like”
representation (using UML Activity Diagrams). The system translates
DL language into a workflow and give Teachers the opportunity to
customize the resulting workflow, by removing/modifying paths. Since
we use a workflow representation, Teachers can focus on customizing
more precisely the fruition of their courses. Starting from the
same RL-LO (i.e. "Analysis"), Teachers can derive multiple
DL-LO (i.e. "Analysis for mathematics" and "Analysis
for physics"); each one represents a sort of "specialization"
of the RL-LO.
Fruition Level (FL)
Starting from DL, further Preconditions and Postconditions are
added and the system is able to generate a particular description
(FL) used as input of a workflow application. The LO is now "published"
and the workflow application will control the fruition of the CLO,
presenting to each Learner the LOs she is allowed to use. Starting
from the same DL-LO, Teachers can publish multiple FL-LO (i.e. "Analysis
for physics, 1st semester 2003" and "Analisys for physics,
2nd semester 2003"); each one represents a sort of "instantiation"
of the DL-LO.
Virtual Campus three-level model
Virtual Campus metadata (VC-LOM)
Metadata is data about data, descriptive information
about resources for the purpose of finding, managing, and using
them more effectively. We use this system of labels to describe
a resouce or object's characteristics and its objectives. The purpose
of metadata is to provide a common means of describing things (electronically)
so that we can define, search, and find learning objects (however
they are defined).
The goal of the Virtual Campus information model (VC-LOM, Virtual
Campus - Learning Object Metadata) is to specify of the LOs' structure
in terms of metadata and contents (references to raw data). The
VC-LOM is based on an extended version of the IEEE LOM. The figure
below shows VC-LOM main components, data elements describe a learning
object and are grouped into categories. The base scheme consists
of nine such categories.
VC-LOM main componenents
We focus especially on Relationships beetwen LOs,
Precondition/Postconditions and Interaction modalities.
Semantics of IEEE LOM Relation metadata is not so
clear. We introduced a new vocabulary for Relation metadata and
defined precise semantics for each relationship. Then, we used relationships
in order to express didactical dependencies beetwen LOs (i.e. "In
order to undertand Derivatives, a student must study Limits"
is represented as "Limits IsRequiresBy Derivatives") that
represents constraints to the fruition of LOs. We use Relation metadata
to store our RL language. Due to the precise semantics we defined
for each relationships, a translation process can generate a workflow
description (our DL language). The generated workflow will respect
the constraints introduced using the relationships.
Preconditions and Postconditions have been added to
express particular constraints that regulate LO access. As an example,
we consider time constraints (start time and end time of a LO representing
a live lesson), administrative properties of Learner, educational
requirements a learner should possess in order to exploit
successfully the LO (however, these are just suggestions: the system
doesn't consider them during the translation process), etc.
VC-LOM supports several "interaction modalities"
in order to make use of diverse LO contents and allows cooperation
among Learners and between Learners and Educators. In particular:
- LO fruition can either be individual or require a group participation.
If a group is required, LO metadata must specify the related cardinality.
- LO collective fruition can either be "synchronous"
(all participants to a group must be on-lime at the same time)
- LO fruition can either be "auditable" by other Learners
or "not auditable".
- LO fruition can require the presence of one or more "guides"
(supervisors). If supervisors are required, LO metadata must specify
supervisors’ rights and group cardinality.