Achieving Collaborative Context-situated Learning by
Distributed Remote Experimentation.
Nelson Baloian1, Stepahn Buschmann 2, Heins Ulrich Hoppe2, José A. Pino1
1Universidad
2Universität
de Chile, Departamento de Ciencias de la Computacion, Blanco Encalada
2120, Santiago, Chile
{nbalioan, jpino}@dcc.uchile.cl
Duisburg, Institute for Computer Science and Interactive Systems, Lotharstr. 63
47048 Duisburg, Germany
{ hoppe, buschmann }@collide.info
Abstract.
In this paper we present a software system implementing a remote synchronous
collaborative “battleship” game which can be played by two persons. The
system provides two different interfaces, one to be used by sighted people and
the other to be used by blind people, thus allowing sighted and blind people
play against each other, without knowing if the adversary is a sighted or blind
person. The interface for sighted people gives mainly information about the
status and development of the game trough a graphical interface. The paper
covers issues the development of a framework which allows the
synchronisation of heterogeneous applications sharing only some common
objects, which is the key for developing collaborative applications with very
different interfaces, as is the case of this work.
1. Introduction: Learning Theories
Earthquakes are normally associated with feeling of fear and destruction. However we
will see in this paper that earthquakes can also be useful to teach some principles of
physics (waves) and mathematics (geometry) to schoolchildren in a very natural way,
with high motivation and in a collaborative way. Earthquakes are very common
phenomena in the central part of Chile [referencia]. Because of this, it is quite natural
that the population of these countries show interest in knowing more about them like
how do they originate, where do they happen, how they propagate and how can we
measure them.
The “context situated learning” theory states that "Activity, concept, and culture are
interdependent", and that "Authentic activity ... is important for learners because it is
the only way they gain access to the standpoint that enables practitioners to act
meaningfully and purposefully”. This supports our idea that students will learn much
better and will achieve acquisition of meaningful knowledge if they learn about a
subject, which is a part of their life.
Autentic activities: .....
Problem of stating a common goal for collaborating ....[johnassen]
Based on these learning theories, a collaborative web-based learning system was
developed which consists involves the monitoring of earthquakes by a set of sensors
and the calculation of its epicenter. One of the most difficult issues for achieving
collaborative learning is to convince the students to collaborate. Setting a goal, which
can only be achieved if they collaborate, can encourage this. In this case, the goal is to
calculate the epicenter of the earthquake.
2. The Network of Sensors
In Santiago, the capital city of Chile, a set of 8 seismographic sensors was installed
in different schools and attached to computers (figure 1 in red). There is also an
additional network of sensors installed for scientific research in the region (in brown).
In each school a group of students interested in learning more about geophysics and
seismic phenomena is responsible of maintaining and taking care of the sensor and the
computer attached to it. Every time an earthquake occurs, the sensors produce data
about the intensity of the earthquake at a rate of 50 times per second. These data are
sent to the computer and stored in files. Three data-sets recording the intensity of the
movement for a three axis artesian coordinate system is generated: one for the
intensity according to the north-south, one for the east- west and one for the z axis.
The structure of the generated file for one earthquake includes three sections where
these values are displayed separately. It also includes additional information about
date, time, and location of the sensor and duration of the earthquake.
figure 1. The network of seismic sensors
3. What and How can Students Learn
As we said, the goal is to calculate the epicenter of the earthquake. By applying
knowledge about how waves propagate in the ground and some knowledge about
geometry, every group is able to calculate the distance at which the epicenter was
located. This is possible because the earthquake wave´s longitudinal and transversal
components propagate at a different speed (see figure 2). This will have as a
consequence that a single and compact waveform produced by an earthquake will
have two impacts on a sensor one resulting from the dispersion of the longitudinal and
another from the transversal component of the wave.
figure 2. Propagation of a seismic wave
Because the longitudinal wave travels faster in the ground, it will reach the sensor
first. Both velocities are known, therefore by using simple path-time law it is possible
to calculate the distance at which the earthquake originated. This is the distance to the
hypocenter, which is the point under the earth surface where the earthquake was
generated. It may be located several kilometers beneath the ground surface and it is
still not known in which direction is this point located. This distance defines a radius
of an hemisphere beneath the ground surface with the location of the specific sensor
as its center (see figure 2). At least the data generated by two additional sensors with a
different location are needed to find the location of the hypocenter and then the
epicenter with some degree of accuracy.
The data of these two additional sensors will define also two more hemispheres
under the surface of the ground. The intersection of all these hemispheres marks the
volume in which the hypocenter is located. To find this point, it is necessary to vary
the depth and minimize the intersection. So iterations must be done starting with a
depth of zero kilometers and increasing it until the intersection is minimal. This is the
point where the hypocenter is located. The epicenter is the projection of the
hypocenter on the ground surface and marks the point where the earthquake had its
bigger intensity.
figure 3. Calculating the position of the hypocenter by iterations
Another procedure allows a single group to calculate the location of the hypocenter
without using data from other groups. This can be achieved by
4. The Learning Environment
By setting the network of sensors and the servers only half of the work is done. We
must also provide the students with a framework where they can do the necessarily
graphics and calculations to determine the distance to the epicenter, share the date
with all other group with a sensor which was also hit by the earthquake and share and
discuss the results with them in order to really achieve collaborative learning. The
need to collaborate follows from the need to share data and process them
collaboratively in order to find the epicenter, as explained in point 3. The tool which
students use is a program implementing the following functionality:
Retrieve data from the local seismogram
Publish the local data on the common server
Download data from seismograms located remotely
Provides a framework where students can do their calculations and graphic
operations in order to find the epicenter
Provides a framework to compare and analyze the results obtained by other groups
Provides a discussion framework
The most interesting feature of the system is the way it supports the students in their
calculations and graphics. For this, it provides a working area, which is meant to
support the workflow of the students' activities. A workflow is represented as a
network of different types of nodes, each one implementing a step further towards the
calculation of the epicenter. The nodes have different functionalities and appearance
(figure 4).
figure 4. The workspace with different kind of nodes
One node is capable to read and store the data of a file generated by a seismogram. It
displays some useful informations about it like date and duration of event. Another
node is able to graphically display this information, if the students connect them by an
edge. With this, the students can easily determine the time lag between the primary
and secondary wave, just by marking this space in the graphic node (like seen in
figure 1). This time lag is the basis for further calculations as mentioned above.
Another node, called “calculation node” uses this value to calculate the distance
dependent on the time lag and the iteratively choosen depth. Establishing a connection
with another node called “Map Node” displays on one hand the map of the specific
region eg. Santiago de Chile and on the other hand the calculated distances. Using this
two-dimensional top view the minimum of the intersection can easily be found.
5. Learning by Collaborating
Developers of collaborative learning systems have often cited Vigostky's Social
Development Theory. According to Bellamy [designung..], three principles form
design of educational environments have been derived from Vigotsky's work:
 Authentic activities: Children should have access to, and participate in, similar
cultural activities to those of adults and should be using age-appropriate tools and
artifacts modeled on those used by adults,

Construction: Children should be constructing artifacts and sharing them with
their community,
 Collaboration: Educational environments should involve collaboration between
experts and students and between individual learners and fellow learners.
We will now show how this system supports Vigotsky's principles of educational
technology.
The system creates the environment for authentic activities because it gives the
possibility to the students to mimic the activities professional people do while
monitoring and recording earthquakes, as well as calculating some characteristics of
them. The system gives the appropriate scaffolding for doing transformation of data
and calculating complicate formulas.
The Freestyler documents permit the collaborative construction of the workflow
for calculating the characteristics of the earthquake, which they can share with the rest
of the community. We will see also in the next chapter how can they construct
physical artifacts to model the earthquake.
This setting allows different kinds of collaborative learning activities:
Collaboration inside one group: the group trying to calculate the distance to the
hypocenter, based on group's data. The tool supports asynchronous collaboration by
annotating and recording the work of each participant. Creating coupled sessions
supports synchronous distributed collaboration. For this the tool was integrated with
MachMaker [referencia]
Collaboration among groups in the same earthquake region: exchanging data
Collaboration among groups in different regions:
6. Visualizing Results
7- Conclusions
Because the sensor network is connected to the world-wide-web, students of any part
of the world may be able to also do the same calculations and learn from an
earthquake, which occurred far away. The initiative to install sensors in schools is not
new. There are some similar initiatives in the USA, France and one is being set up in
Japan. The main contribution of this work is to generate a platform, which supports
the collaborative learning for. This work is part of a bigger project named Coldex,
which deals with the problematic of achieving true learning through remote
collaborative monitoring or experimentation. There have been many initiatives around
the world to make experiments available though the Internet, for example, setting up
systems which allow students from school to remote control a telescope and capture
images from the sky. In our opinion, this is only the first part of the work, which
should be done in order to achieve meaningful learning through remote, or distributed
collaborative experimentation. There must be also a system supporting the learning
process though the proposition of concrete learning activities. In the Coldex project
we are also developing an environment for putting a telescope online. This initiative
considers the development of a supporting system which will allow the students to
simulate the scientific work and procedures professional astronomers do. This
includes:
Requesting observation time by submitting a proposal discussing why is their
observation proposal interesting (what do they want to learn)
Select from all the proposals submitted by their pears by voting
Publish their results
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