STUDENTS UNDERSTANDING OF ELEMENTARY ASTRONOMY

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STUDENTS UNDERSTANDING OF ELEMENTARY ASTRONOMY
1st Feb 2008

• Shamin Padalkar
• Thesis Advisor Prof. Jayashree Ramadas
• HBCSE

ASET
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Plan

• Introduction
• Methodology
• Sample
• Findings
• Pedagogy

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Introduction

• Why learn astronomy?
• Astronomy is exciting
• It helps explain everyday phenomena
• It challenges astrology
• What astronomy do students learn?
• Heliocentric model of solar system and
  explanation of daily phenomena (day-night,
  seasons, phases of moon, eclipses)
• A few elementary facts in cosmology

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Problem

• Students and adults have problems in
  understanding the heliocentric model and using it
  to reason about daily phenomena (Bailey et al.
  2004). For example,
• Day-night occur due to the sun moving around the
  earth or the sun hiding behind hill/ moon.
  (Vosniadou and Brewer, 1994)
• Seasons occur due to variation in distance of the
  earth from the sun due to elliptical orbit
  (Baxter, 91)
• Phases of the moon occur due to shadow of the
  earth falling on the moon (Stahly et al 1999,
  Padalkar and Subramaniam 2007)

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Theoretical background

• A useful dichotomy from artificial Intelligence
  Mental representation and processes.
  Representations could be propositional or
  perceptual.
• A mental model may contain visual-spatial as
  well as conceptual information. It is flexible.
• Spatial abilities enable us to process an image
  or a model to derive or explain consequences
  (Hegarty, Waller, 04)
• Spatial visualization Ability to imagine spatial
  forms and movements including translations and
  rotations
• Spatial orientation Perspective-taking
• Mental simulation Running visual-spatial mental
  models

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• Either a model could be wrong or
  the reasoning based on the model might go
  wrong.

Careful observations
Building skeletal mental model
Predictions
Explain phenomena
Refining the mental model
Examples solar/ stellar model, model of pulsar,
universe
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Methodology

• Pretest in the beginning of the first cycle (Std.
  4, 7)
• Observations
• Explanations
• Three cycles of contact session (Std. 7-8)
• Cycle I Earth (roundness and rotation)
• Cycle II Sun-Earth system (revolution, parallel
  sun-rays)
• Cycle III Sun-Earth-Moon system
• Post test at the end of the last cycle
• Interviews of selected students

• Textbook information
• Cultural information

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Sample

• Std. 7 - 8 students from three schools in the
  State of Maharashtra Medium of instruction
  Marathi
• Students from low educational and economic
  backgrounds - first generation learners
• High drop-out (Rural primary- 90, middle
  school- 69, college- 18) especially for girls

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Ethnography

• Urban Slum area of Mumbai
• Tribal Residential school for nomadic tribal
  children
• Rural Farming village near Kolhapur, school in
  a single building of a temple
• Schools have limited resources Students often
  come to class without minimal tools such as
  pencils, erasers
• Access to indigenous knowledge and opportunities
  to observe clear skies

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Findings

• Some observations on std. 7 students from the
  pre-test follows in the next few slides.

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Most students know few observational facts such
as...

• 84 knew that the shape of the moon changes every
  day.
• 44 students knew that moon is not seen every
  night
• 65 students stated that the stars dont remain
  in the same position throughout the night and
  over the year.
• 48 students knew that place of sunrise and
  sunset changes everyday.
• 39 recalled having seen a shooting star.

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Habit of careful observations is not cultivated.

• Only 3 students knew that the sun does not come
  overhead everyday.
• Students could not describe the direction of
  sunrise and sunset within their own surroundings.
• 24 students responded that they have seen a moon
  in daytime but 70 drew its picture (crescent 34
  full moon 21 half moon 8 gibbous 7)
• In the night sky observation session, students
  could not identify any of the planets, stars or
  star-groups, but had heard some of their names
  and had seen pictures of planets in their
  textbooks.

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Visual observations are more prominent than
spatial

• What does the setting sun look like?
• Responses based on colour (reddish, orange,
  yellow, golden)- 78
• Shape (bigger, round, half)- 14 position (east,
  down)- 4 18
• Differences between the setting sun and the sun
  at top?

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Explanations of facts are inadequate

• 30 students said that stars are present in the
  sky during the day but 18 could explain that
  stars are not seen in the day due to sun-light.
• Students did not relate the apparent motion of
  the celestial bodies with a common cause, in this
  case, rotation of the earth.

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Most students are familiar with terms from their
textbooks such as...

• Earth is where we live, living organisms,
  environment, planet, made up of soil, land,
  egg-like shape, blue, revolves
• 60 - 75 students knew the terms star, planet
  and satellite and could correctly match these
  terms with a few specific cases.
• Students could approximately correctly show in
  diagrams Equator (67), North Pole (60),
  South Pole (62), orbit of the earth (53)
  and orbit of the moon (7)

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Students are not familiar with some very useful
concepts such as...

• None of the students knew the observational
  meaning of horizon although some had heard the
  word (kshitij in Marathi) in a literary or
  poetic context.
• Concept of axis although the rotation is taught
• Ray diagrams to draw shadows When students were
  asked to draw a shadow of a vertical stick none
  of the students used any geometrical method using
  the direction of the sun rays to locate the
  shadow. Only 50 showed sun and the shadow to be
  on opposite sides.

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An example of rote learning

• 82 students knew that the earth moves.
• 67 mentioned rotation or revolution or both
  rotation and revolution.
• Surprisingly more number of students (70) could
  state the time periods of rotation and
  revolution. Almost all of the remaining students
  stated the correct numbers but interchanged
  rotation with revolution.

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Even diagrams can be rote learnt

• 73 students reproduced the correct textbook
  diagram for explanation of day and night though
  only 9 wrote an explanation for the apparent
  movement of the sun in terms of the earths
  rotation.
• Although 98 students produced correct a diagram
  of the earth, none of the students responded
  correctly to questions which had physical
  significance (eg. where do we live on the earth?)

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But some intuitive understanding does exist

• For a question what would happen if the earth
  stopped rotating ? 62 responded that day and
  night would not occur (an intuitive connection
  between rotation and day-night exists).
• When asked specifically if the stars and moon
  would still appear to move, 25 said no, they
  would not. Only two students answered correctly
  that only the moon would continue to move.

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Students do not have good idea of spatial
properties such as shape and size

• 38 could rank the sequence (shooting star, moon,
  earth, sun) by size.
• In a sub-sample of 18 students, only 1 student
  could rank the bodies (lightning, moon, sun, Pole
  star) by their distance from the earth.

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Students have erroneous models of the earth even
in Std. 7

• 98 students showed a roughly round earth in
  their diagrams. 60 students said that the earth
  is round like a ball,
• But at least 15 showed people inside the earth -
  hollow earth
• a bowl (2)
• Earth is like an egg (23)
• a plate (13) (none in urban sample)

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Gravity is not integrated with spatial properties
of the earth

• All the students drew people oriented vertically
  or almost vertically within the frame of the
  paper.
• 75 showed these people inside the circle
  denoting the earth (Excluding hollow earth
  model), while 9 showed at least a few people on
  upper one-fourth portion of the perimeter
• 47 students drew rain only on the upper half of
  the round earth while 11 drew it inside the
  earth. Only 9 drew the rain falling (radially)
  around the upper two-thirds portion.

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Indigenous knowledge

• Indigenous knowledge is tied with cultural
  practices and tools such as almanacs and
  calendars
• Indigenous calendars were developed on the basis
  of observations, but now use tabulations and
  calculations
• Hindu calendars are lunisolar
• They are still used to organise agricultural
  activities and festivals (celebrated socially and
  by schools)
• Students in our sample, all being from the Hindu
  community are familiar with a version of Hindu
  calendar (Chaitri Panchang) integrated with
  Gregorian calendar. (Kaalnirnay, Mahalaxmi)

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Local calendars

• Indigenous calendars contain notings on numerous
  observational facts such as
• Phase of the moon
• In which division of the sky and zodiac sign the
  moon is seen
• Daily times of sunrise and sunset,
• Times of moonrise and moonset on important days
• Name of the month, which shows which star group
  or nakshatra is visible on the sky through the
  night.

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Students know the terms and facts from indigenous
knowledge

• 75 students could name 6 or more of the Marathi
  months
• 45 students could name 6 or more of the zodiac
  signs

• Moon rise timings may be associated with fasts.
• 40 students responded that they have heard about
  Sun in a nakshtra, but do not know the meaning
  of the term. Others have not heard it.

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But students do not know observational
significance of those terms.

• When asked to list names of festivals occurring
  on different phases of moon, students were
  puzzled. After a hint 60 students wrote 476
  responses, out of which 65 correctly matched the
  festival with the phase of the moon. (Amawasya
  and Dwitiya were the difficult ones)
• Students did not know that Zodiac signs are the
  star patterns in the sky. Although they knew that
  nakshatras are star pattern, they do not know
  their connection with names of months.

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Indigenous knowledge is tied up with astrology

• Students were familiar with phrases such as
  birth under a zodiac sign or starting of a
  nakshatra. More (20) students knew about zodiac
  signs (which have astrological meaning) than they
  knew names of nakshatras (8) (which have a
  significant time keeping role in astronomy).
• 43 students stated that they do believe in
  astrology, while only 17 said they did not.

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Conclusions

• The responses from tests show that
• Facts and terminology (from both textbooks and
  indigenous resources) are learnt in an uncritical
  manner.
• Misunderstandings are common.
• The information is fragmented and does not serve
  to create a coherent model for comparison and
  reasoning.
• Astrological context is strong.

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Implications for pedagogy

• Observational base of daily events needs to be
  built
• Models need to be developed from the information
  they have gained from textbooks, beginning with
  their model of a round, rotating earth
  incorporating the notion of gravity
• Information that they have gained from their
  indigenous sources needs to be integrated with
  their observations and with their mental models

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Role of models and diagrams

• Spatial tools Concrete (physical) Models,
  Diagrams
• Models 3D, realistic (geosynchron) (Monteiro)
• Constraints on concrete models in astronomy
  (Albanese et al. 97)
• Models cannot incorporate scale information,
  change of perspective and also most aspects of
  motion
• Not suitable for reasoning
• Diagrams are permanent over space and time, can
  serve as tool for reasoning (Tversky, 2005)
• Problems with schematic diagrams 2D, Static,
  abstract

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The gesture link

• From cognitive science studies we know that
  kinesthetic feedback is helpful in changing
  perspective and rotating objects mentally
  (Klatzky et al, 1998)
• Body movements and gestures can be used to link
  model to observation
• Gestures are dynamic, three dimensional
• So they can be used to relate physical models to
  diagrams
• eg Rotation of body and body-parts and right
  hand thumb to understand axis Curvature
  decreases as the radius increases

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Diagrams

• Through models and gestures we arrived at
  schematic diagrams.
• Diagrams were developed on the blackboard along
  with the teacher-student dialog
• Students drew diagrams within interactive reading
  material based on history. They also drew
  diagrams to depict and explain their observations
  and aspects of the model.

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Work in progress...

• The teaching cycles are to be concluded. The post
  tests will help evaluate the effectiveness of the
  pedagogy.
• For pedagogy refer
• Padalkar, S. and Ramadas, J. (2008). Modeling the
  round earth through diagrams, Astronomy Education
  Review. HTML http//aer.noao.edu/cgi
  -bin/article.pl?id254
  PDF http//aer.noao.edu/figures/v06i02/06-02-01-0
  4.pdf
• For students ideas refer
• Padalkar, S. and Ramadas, J. (forthcoming).
  Indian students' understanding of astronomy.
  Paper Submitted for Conference on Asian Science
  Education - 2008.

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References

• Albanese, A., Danhoni Neves, M. C. and Vicentini,
  M. (1997). Models in science and in education A
  critical review of research on students' ideas
  about the earth and its place in the universe. -
  (Kluwer acadamic publishers, 1997)
• Bailey, J. M., Prather, E. E., Slater, T. F.
  (2004). Reflecting on the summary of astronomy
  education research to plan for the future,
  Advances in space research, 34, 2136 - 2144.
• Baxter (1991) Hegarty, M. and Waller, David A.
  (2005). Individual differences in spatial
  abilities. In Priti Shah and Akira Miyake (Eds.),
  Handbook of Visuospatial Reasoning. New York
  Cambridge University Press. 121-169. 213-256.)
• Hegarty, M. and Waller, D. (2004). A distinction
  between mental rotation and perspective taking
  spatial abilities. Intelligence, 32, 175 - 191
• Klatzky R. L. and Loomis J. M. (1998). Spatial
  updating of self position and orientation during
  real, imagined, and virtual locomotion.
  Psychological Science, 9, 293 - 128
• Monteiro, V. http//hsb.iitm.ac.in/\jm/ARCHIVES/J
  an-Feb06/article\_files/discover\_it\_4.html
• Padalkar, S. and Subramaniam, K., (2007)
  Reasoning processes underlying the explanation of
  the phases of the moon. In C.Natarjan and
  B.Choksi (eds.) Proceedings of Episteme-2
  International Conference, New Delhi, Macmillan
  India, 121-125.

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References

• Ramadas, J., (2007). Visual-spatial modes in
  science learning, In C.Natarjan and B.Choksi
  (eds.) Proceedings of Conference epiSTEME-2,
  International Conference, New Delhi, Macmillan
  India, 9
• Samarapungavan, A., Vosniadou, S. and Brewer, W.
  F. (1996) Mental models of the earth, sun and
  moon Indian children's cosmologies. Cognitive
  Development, 11, 491 - 521
• Stahly, L. L., Krockover, G. H., Shepardson D. P.
  (1999) Third grade students' ideas about the
  lunar phases, Journal of Research in Science
  Teaching, 36, 2, 159 - 177
• Subramaniam K. and Padalkar S., (forthcoming)
  Proposal accepted for a special issue of the
  International Journal of Science Education on
  Visual and Spatial Modes in Science Learning
• Tversky, B. (2005). Visuospatial reasoning.
  Chapter 10 in K. Holyoak and R. Morrison (eds.),
  The Cambridge Handbook of Thinking and Reasoning.
  Cambridge (Chapter 10), MA Cambridge University
  Press.
• Vosniadou, S., Brewer, W. F. (1994). Mental
  models of the day/night cycle. Cognitive Science,
  18, 123183.

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Thank You!

• We thank Ms. Jyoti Kumbhare and Mr. Vikas Patil
  for help with classroom organization and data
  handling. Thanks to administration and students
  of all three schools, and HBCSE staff.