This document describes the design and development of a learning progression about stellar structure and evolution (SSE). The researchers created three levels of a learning progression based on dimensions of hydrostatic equilibrium, composition and aggregation state, and functioning and evolution. They interviewed students before and after instructional activities to map their understanding to the levels. The findings showed statistically significant shifts in students' understanding along the levels after instruction, providing evidence that the learning progression can describe how student understanding of SSE develops with instruction.

1. Italo Testa et al. Design and Development of a Learning Progression about SSE
Italo TESTA1
Arturo COLANTONIO2,3,, Silvio LECCIA3, Silvia GALANO1, Emanuella PUDDU3
1 Department of Physics “E. Pancini”, University Federico II, Naples, Italy
2 Physics Division, School of Science & Technology, University of Camerino, Camerino, Italy
3 INAF, Astronomical Observatory of Capodimonte, Naples, Italy
Design and Development of a
Learning Progression about
Stellar Structure and Evolution
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2. Italo Testa et al. Design and Development of a Learning Progression about SSE
Introduction
Research in science education increasingly promotes use of
Learning Progressions (LPs) to describe and interpret how students
develop their understanding of a given concept across school
levels
(Corcoran, Mosher, & Rogat, 2009)
Introduction
and aims
Methods
Findings
Conclusive
remarks
2

3. Italo Testa et al. Design and Development of a Learning Progression about SSE
• Areas of astronomy covered by LPs so far:
 Celestial Motion
 Change of seasons (Willard and Roseman, 2007; Sneider, Bar, & Cavanagh, 2011; Plummer & Maynard, 2014)
 Motion of the Sun and Moon (Plummer, 2009; Plummer and Krajcik, 2010)
 Moon phases (Plummer, 2012)
 Seasonal changes, Moon phases, solar and lunar eclipses (Testa et al., 2015)
 Solar system formation (Plummer et al., 2015)
• Astronomy and astrophysics areas at higher level of education
partially covered
Introduction
and aims
Methods
Findings
Conclusive
remarks
Introduction
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4. Italo Testa et al. Design and Development of a Learning Progression about SSE
A LP about Stellar Structure and Evolution (SSE)?
• SSE provides meaningful explanatory models for a broad
range of phenomena in the field of astronomy:
• presence and production of heavy elements
• conditions under which life has developed in the Universe
• improvement and validation of models of the Universe
4
Introduction
and aims
Methods
Findings
Conclusive
remarks
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5. Italo Testa et al. Design and Development of a Learning Progression about SSE
• SSE is related to students’ learning of
• how life on Earth depends on the Sun
• indirect inquiry methodologies used in physics
• core concepts in classical and modern physics
• Connection with other big ideas in Astronomy:
• size and distances
• galaxies
• Universe
5
Introduction
and aims
Methods
Findings
Conclusive
remarks
A LP about Stellar Structure and Evolution (SSE)?
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6. Italo Testa et al. Design and Development of a Learning Progression about SSE
Research question
How do students progress in their understanding
about SSE when exposed to iteratively designed
instructional activities in a LP framework?
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Introduction
and aims
Methods
Findings
Conclusive
remarks
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7. Italo Testa et al. Design and Development of a Learning Progression about SSE
Research design
Introduction
and aims
Methods
Findings
Conclusive
remarks
Design
Assessment
&
Revision of LP1
Re‐Design of TLS1
Assessment
&
Revision of LP2
Interviews
Literature
Curriculum
Interviews
Literature
Curriculum
Interviews
Classroom
implementations
Interviews
Classroom
implementations
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8. Italo Testa et al. Design and Development of a Learning Progression about SSE
Students’ understanding of SSE
• Incorrect students ideas (Finegold & Pundak, 1990; Raypaul et al., 2018):
• stars and planet;
• Milky Way composed by close stars;
• distance between stars and Earth;
• stars are motionless
• Confusion between chemical and nuclear reactions (Agan, 2004)
• Role of gravity (Bailey, 2006)
• H‐R diagram as a “real” trajectory(Agan, 2004)
• No other study so far identified increasingly sophisticated reasoning
about SSE
Introduction
and aims
Methods
Findings
Conclusive
remarks
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9. Italo Testa et al. Design and Development of a Learning Progression about SSE
Italian school curriculum about SSE
Introduction
and aims
Methods
Findings
Conclusive
remarks
celestial objects
celestial sphere
stars’ composition
life cycle of stars
HR diagram
galaxies
origin of the
Universe
Earth sciences
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Palmieri &
Parotto, 2012

10. Italo Testa et al. Design and Development of a Learning Progression about SSE
Choice of LP dimensions
Functioning and
Evolution
Composition and
aggregation state
Hydrostatic
equilibrium
Introduction
and aims
Methods
Findings
Conclusive
remarks
GravityGravity
TemperatureTemperature
Nuclear
reactions
Nuclear
reactions
MassMass
…….…….
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11. Italo Testa et al. Design and Development of a Learning Progression about SSE
Instrument
• 20‐minutes, seven‐question interview adapted from an existing
multiple‐choice instrument (Bailey et al., 2012)
• Composition and aggregation state:
• What is a star?
• What is the composition of a star?
• Draw the shape and internal structure of a star. Briefly explain your drawing
• Hydrostatic equilibrium
• Do you think that a star is a system in equilibrium?
• Functioning and evolution
• How does a star form?
• What is the main mechanism underlying stars’ functioning?
• How would you describe the final stages of the life of a star?
Introduction
and aims
Methods
Findings
Conclusive
remarks
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12. Italo Testa et al. Design and Development of a Learning Progression about SSE12
Data analysis(Minstrell’s “facets”, 1992)
Introduction
and aims
Methods
Findings
Conclusive
remarks
Facets
LP levels
Lower anchor
Level 1
Upper anchor
Student 1
Student 2
Student 3
Student n
Spontaneous
(a)
Spontaneous
(a)
Spontaneous
(b)
Spontaneous
(b)
Spontaneous
(j)
Spontaneous
(j)
Scientific (a)Scientific (a)
Scientific (b)Scientific (b)
Student i
Coding
Mapping
Inter‐rater reliability = 0.88; 0.94; 0.95
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13. Italo Testa et al. Design and Development of a Learning Progression about SSE
Samples involved
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Introduction
and aims
Methods
Findings
Conclusive
remarks
Sample 1: N = 77,
 30 first year (13‐14 years old), 47 fifth year (17‐18 years old) students
after curriculum instruction
Sample 2: N = 20,
 17‐18 years old after TLS1
Sample 3: N = 30,
 17‐18 years old after TLS2
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14. Italo Testa et al. Design and Development of a Learning Progression about SSE
Findings – LP1
Level Hydrostatic Equilibrium
Upper Anchor Balancing gravitational force and radiative pressure
forces
Level 2 Incomplete balancing of forces
Level 1 Recognized but qualitative
Lower Anchor Structure not in equilibrium
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Introduction
and aims
Findings
Conclusive
remarks
Methods
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15. Italo Testa et al. Design and Development of a Learning Progression about SSE
Level Composition and aggregation state
Upper Anchor H and He recognized, mass, temperature, radius.
Spherical shape. Internal structure justified
Level 2 H and He recognized, mass, temperature, radius.
Spherical shape. Internal structure incomplete
Level 1
Made of gases. Spherical shape. Internal structure not
recognized.
Lower Anchor
Made of dust, gases or result of collisions. H and He
not the main constituents. Shape not recognized.
Internal structure not recognized.
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Introduction
and aims
Findings
Conclusive
remarks
Methods
Findings – LP1
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16. Italo Testa et al. Design and Development of a Learning Progression about SSE
Level Functioning and evolution
Upper Anchor Gravity is correctly recognized. Stellar functioning qualitatively
justified. Life/death stages justified in terms of mass
Level 2 Gravity is recognized but role is unclear. Stellar functioning
qualitatively justified. Final stages incorrectly described
Level 1 Formation is attributed to a generic attraction. Nuclear reactions
important but role is unclear. Final stages incorrectly described
Lower Anchor
Gravity not recognized in formation. Nuclear reactions
important but confused with chemical reactions. Final stages
incorrectly described.
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Findings – LP1
Introduction
and aims
Findings
Conclusive
remarks
Methods
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17. Italo Testa et al. Design and Development of a Learning Progression about SSE
Findings – Distribution in LP1 levels
Hydrostatic equilibrium*
(* p<10‐4)
Introduction
and aims
Findings
Conclusive
remarks
Methods
Comp. and aggr. state **
(** p =0.042)
Functioning and evolution ns
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18. Italo Testa et al. Design and Development of a Learning Progression about SSE
TLS1 activities
(Leccia et al., 2015; Colantonio at al. 2016)
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Introduction
and aims
Findings
Conclusive
remarks
Methods 2
3 2
2 2
2
5.7*10 ;
2.7*10S
v
ms
R
GM
ms
R
 



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19. Italo Testa et al. Design and Development of a Learning Progression about SSE
Sample 2 (N = 20)
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Introduction
and aims
Methods
Findings
Conclusive
remarks
Marginal homogeneity test: p < 0.005; p < 0.008; p < 0.001
Hydrostatic equilibrium Comp. and aggr. state Functioning and evolution
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20. Italo Testa et al. Design and Development of a Learning Progression about SSE
TLS2 activities
(Colantonio at al. 2016)
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Introduction
and aims
Findings
Conclusive
remarks
Methods
4
H He
 
2
15
2 1
,
1
hc
k T
hc
I T
e 


 
 
 
 
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21. Italo Testa et al. Design and Development of a Learning Progression about SSE
Sample 3 (N = 30)
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Introduction
and aims
Methods
Findings
Conclusive
remarks
Marginal homogeneity test: p < 10‐4
Hydrostatic equilibrium Comp. and aggr. state Functioning and evolution
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22. Italo Testa et al. Design and Development of a Learning Progression about SSE
Findings – Final LP (LP3)
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Level Hydrostatic Equilibrium
Upper Anchor Balancing gravitational force and radiative pressure forces
Level 4 Role of thermodynamics recognized but mechanism
underlying balancing pressure forces is unclear
Level 3 Balance of forces is unclear
Introduction
and aims
Methods
Findings
Conclusive
remarks
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23. Italo Testa et al. Design and Development of a Learning Progression about SSE
Findings – Final LP (LP3)
23
Level Composition/aggregation
Upper Anchor
H and He recognized, mass, temperature, radius. Presence of
heavier elements inferred from spectrum. Spherical shape
recognized. Spectra as result of composition. Internal
structure justified. Variable density
Level 4
Spectra as result of composition. Spherical shape recognized
but not justified. Internal structure recognized but not
justified. Variable density
Level 3
Spectra not associated to composition. Spherical shape
recognized but not justified. Internal structure recognized but
not justified. Variable density
Introduction
and aims
Methods
Findings
Conclusive
remarks
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24. Italo Testa et al. Design and Development of a Learning Progression about SSE
Findings – Final LP (LP3)
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Level Functioning and evolution
Upper
Anchor
Gravity determines spherical shape. Relationship between
surface temperature and inner processes. Nuclear reactions are
related to evolution and production of elements. Role of mass
qualitatively justified
Level 4
Gravity role in birth partially described. Relationship between
surface temperature and inner processes. Nuclear reactions are
related to evolution and production of elements. Role of mass
unclear
Level 3
Gravity role in birth unclear. Relationships between surface
temperature and inner processes. Role of nuclear reactions in
evolution unclear. Role of mass unclear
Introduction
and aims
Methods
Findings
Conclusive
remarks
24

25. Italo Testa et al. Design and Development of a Learning Progression about SSE
Discussion
• The three chosen dimensions of SSE LP
i. explain a variety of phenomena
ii. are representative of concepts taught in high school syllabi
iii. encompass high school students’ relevant ideas
o Further dimensions to include undergraduate students’ ideas?
• The three chosen dimensions of SSE LP
i. explain a variety of phenomena
ii. are representative of concepts taught in high school syllabi
iii. encompass high school students’ relevant ideas
o Further dimensions to include undergraduate students’ ideas?
25
Introduction
and aims
Methods
Findings
Conclusive
remarks
25

26. Italo Testa et al. Design and Development of a Learning Progression about SSE
Discussion
• Findings confirm and extend prior work
(Agan, 2004; Bailey, 2006; Bailey et al, 2009; Plummer et al., 2015)
• Role of gravity in SSE
• Combination of dynamics, thermodynamics and hydrostatics to explain
equilibrium
• Confusion between chemical and nuclear reactions
• Production of elements until Fe
• Findings confirm and extend prior work
(Agan, 2004; Bailey, 2006; Bailey et al, 2009; Plummer et al., 2015)
• Role of gravity in SSE
• Combination of dynamics, thermodynamics and hydrostatics to explain
equilibrium
• Confusion between chemical and nuclear reactions
• Production of elements until Fe
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Introduction
and aims
Methods
Findings
Conclusive
remarks
26

27. Italo Testa et al. Design and Development of a Learning Progression about SSE
Implications ‐ LPs
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Introduction
and aims
Methods
Findings
Conclusive
remarks
27

28. Italo Testa et al. Design and Development of a Learning Progression about SSE
Thank you for your attention!
How to get a copy of the paper:
https://journals.aps.org/prper/abstract/10.1103/PhysRevPhysEducRes.14.010143
italo.testa@unina.it
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