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Astronomical Data Analysis Software and Systems VII
ASP Conference Series, Vol. 145, 1998
R. Albrecht, R. N. Hook and H. A. Bushouse, e
Ö Copyright 1998 Astronomical Society of the Pacific. All rights reserved.
ds.
Teaching Astronomy via the Internet
L.Benacchio, M. Brolis and I. Saviane
Astronomical Observatory, vicolo Osservatorio 5, I­35122 Padova, Italy
Abstract.
In the framework of a partnership between the Astronomical Obser­
vatory of Padova and Telecom Italia, the most important Italian Internet
and Intranet provider, we are experimenting with the educational possi­
bilities of the Internet. A Web site entirely devoted to the teaching of
Astronomy to secondary school students has been designed and realized.
Graphics and animations are widely used to introduce the concepts, and
special care has been devoted to the language used in the text.
A group of junior and senior high schools (8­12 grades) will be con­
nected to a server located in the Observatory, and the server will in turn
be a gateway to the whole Net. Access will be given to a selected number
of external astronomical Web sites.
The actual use of this tool in the selected classrooms will be followed
up in the next scholastic year (October 97--June 98). A strong and con­
tinuous interaction with the teachers is also, obviously, foreseen to ensure
a strong positive feed--back. On one hand, this project will give us im­
portant suggestions for the further development of a specific educational
methods suitable for the Web. On the other, it will give the students
basic astronomical knowledge and the possibility to become familiar with
the Internet environment.
1. Guidelines for this Project
There are several reasons why astronomy is an appropriate choice for a project
like this. Astronomy and astronomical images have immediate appeal to a large
number of young people, so they can be used to attract people to science in
a general sense. Moreover, images are an obvious way to build an attractive
Web site, and a search on the Web does indeed reveal that there is a huge
amount of astronomical information available. On the other hand, there are no
comprehensive projects which lead a student through astronomy from the very
basics, particularly among Italian Web sites. Furthermore, the information that
one can find is also sometimes wrong or misleading. The aim of our project is
therefore first to provide introductory and reliable astronomical material to 8
­to­12 grades students, and, as a second step, to be an informed guide through
the existing external Web sites.
With regard to the first point, the new medium allows one to overcome
the limitations of traditional textbooks: the students can establish by them­
selves the pace of their `lessons', and they can experiment in real time with the
244

Teaching Astronomy via the Internet 245
concepts they have learned, interacting with the environment that we provide.
Furthermore, the Web site also contains a guided first contact to the Internet
and explains how to exploit its wealth of astronomical information.
We must also point out that teachers themselves are not always aware of the
possibilities of the Net, and textbooks are generally lacking in topics suitable for
e#ective hands­on activities. Another important task of our project is therefore
to assemble a complete database of reference hands­on activities to be performed
in the classroom. Guidelines for their usage and simulations of the results are
also given.
2. Theoretical Approach to the Educational Method
It is now widely accepted that the best strategy to introduce new knowledge to
students is the so--called Karplus' cycle (Atkin & Karplus 1962; Karplus et al.
1976). It consists of three steps. First, the students are given some `environment'
where they can explore a given phenomenon, make their own observations and
draw some first conclusions. Second, these preliminary conclusions are discussed
with the teacher and incorrect interpretations are removed. Finally, once the new
and correct explanation is acquired, new concepts are used in the exploration of
a new situation, and the learning cycle repeats itself.
We also bear in mind that new knowledge should be introduced after the
students' misconceptions have been removed. If this task is not performed,
it is possible that no actual change in the individual reasoning will happen.
Her/his knowledge is not restructured (see e.g., Vosniadou & Brewer 1987). The
new information will be somehow adapted to the old mental schemes, so that
distortions and misunderstandings will result. Moreover, the knowledge is never
incorporated into one's vision of the world and soon forgotten (Ausubel et al.
1978).
Once the educational method has been defined, the contents must be se­
lected and organized. The basic approach is to put the subjects in a hierarchical
structure. To this aim, several methods can be devised in order to identify which
concepts are prior to the others, and conceptual pyramids can be built. We fol­
lowed the results of the project STAR, which are discussed in by Sadler (1996,
see his Figure 6).
After this first learning phase, another approach to the educational material
can be given, which is that of unifying concepts. It is useful for the students to
see how the same principles and methods are at work throughout all the subjects
they have encountered.
Educational content and unifying concepts are now briefly discussed.
2.1. Educational Content
The subjects have been selected from a standard list (see e.g., Schatz 1996) and
organized in a multilevel structure. The starting points are the concepts of the
Earth's shape and motion, then we move on to gravity and its consequences,
periodic phenomena and orbits, the laws of planetary motion and the Solar
System. Radiation properties are introduced before studying the Sun and the
stars. The masses, luminosities, radii, temperatures and distances of the stars
are discussed, and care is always used to supply all data in a comparative way.

246 Benacchio, Brolis and Saviane
At the higher levels, our current vision of the structure of the Universe is given,
emphasizing the role of galaxies as the fundamental components of the large
scale structure. Finally, the Big Bang theory is introduced and the past, present
and future of our Universe are discussed.
During a normal school year only a few themes can be explored in depth,
so the teacher will have to select a subset of all the subjects, which should be
consistent with the actual level of her/his students.
2.2. Unifying Concepts
After introducing the fundamental idea of science as inquiry, other conceptual
structures are highlighted, such as energy balance and conservation, the equi­
librium and evolution of a physical system, and the clustering properties of the
Universe. It is shown how the Universe is ordered and organized from micro to
macro worlds. The relation between distances and time scales is emphasized,
and between the mass, radius and luminosity of stars and galaxies. The concept
of order of magnitude of physical quantities is also explored.
3. Application to the Internet Environment.
The misconception removal phase and the learning cycle have been reproduced
by means of tests. In the first case, the questions reproduce the ones used in
many experimental investigations on the children's learning processes and are
connected to a list of answers which contains the most common misconceptions.
If a wrong answer is selected, then its consequences are shown to the student,
and eventually he will get to the point of self­contradiction. From this point he
will get back to the initial test, and when the right answer is chosen the correct
explanation is reinforced by means of other examples, images, films etc.. This
process makes the student interested in the forthcoming material and prepares
him/her for the next subject.
When the test is connected to the Karplus' cycle, it is used to perform the
three phases. First, the exploration of a phenomenon is proposed by means of
introductory text and images, and some observations and/or hands­on activities
are suggested. These observations are usually possible with very simple aids,
and the teacher is expected to guide the students through the various steps. If
for some reason the observations cannot be made, or the user has no time for
them, then simulations are provided. The simulations are also useful as a guide
to the correct interpretation of the observations. Java scripts are widely used in
this phase.
The students are then requested to give their interpretation of the observa­
tions and/or simulations. A set of alternative explanations for the phenomenon
is listed and the students are required to choose one. When the student's choice
is incorrect, they are led to a self­contradiction.
The third phase (application of new concepts) is performed when the correct
answer is chosen. The phenomenon is further discussed and its consequences
highlighted, and it is then used to introduce the next subject in the hierarchy.
CGI scripts have been devised in order to manage the tests and the related
actions, and to take care of the user database and access log.

Teaching Astronomy via the Internet 247
The site is organized in a multiple level structure. The single levels can
be accessed either from a general table­of­contents or through an ordered path.
A log of all the user's accesses is kept. If the user wishes, his/her performance
can be evaluated using the number of correct vs. wrong answers. In that case,
access to the single levels is given with a password and is flagged in the log file.
4. Conclusions and Future Developments
This project allowed us to establish a template in the teaching of Astronomy via
the Internet. The most e#ective educational strategy has been identified and
it has been adapted to the new medium. The key feature of this medium, i.e.,
interactivity, has been fully exploited.
The educational contents have been carefully selected and organized in a
hierarchical structure. Therefore, we ensured both that the basic astronomical
knowledge is provided and that no previous elements are needed to fully exploit
the Web site. The basic unifying concepts have also been identified and are
stressed throughout the various levels.
Browsing through this material, the students will encounter a new way to
learn things. A lively way which overcomes the traditional static textbook lim­
itations, and which gives the students the chance to wander around along their
preferred path at a pace they will establish according to individual capabilities.
They will learn by doing things themselves, which is the best way to learn.
At the same time, the Web site provides a starting point to become familiar
with the Net environment and to establish a minimum set of astronomical con­
cepts. Using this background astronomical knowledge and the basic navigation
skills, they will be able to access the available material on the Web with full
awareness.
In the near future, we will extend the database of interactive experiments
by means of a Java laboratory, and VRML will be implemented. The response
of real classes will be tested and we will take advantage of the students' and
teachers' suggestions in order to improve the site (a 6 month phase is expected).
The Web site can be reached via the Padova Astronomical Observatory 1 .
References
Atkin, J.M., & Karplus, R. 1962, The Science Teacher, 29, 45
Ausubel, D.P., Novak, J.D., & Hanesian, H. 1978. In Educational Psychology:
A Cognitive View. New York, Holt, Rinehart and Winston
Karplus, R., et al. 1976, AESOP Pub. ID­32, Univ. of California, Berkeley
Mestre, J.P. 1991, Phys.Tod., Sep 91, 56
Sadler, P.M. 1996, ASPC, 89, 46
Schatz, D. 1996, ASPC, 89, 33
Vosniadou, S., & Brewer, W.F. 1987, Review of Educational Research, 57, 51
1 http://www.pd.astro.it/