the virtual solar system project: developing conceptual understanding of astronomical concepts...

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Journal of Science Education and Technology pp520-jost-375359 June 20, 2002 12:13 Style file version June 20th, 2002

Journal of Science Education and Technology, Vol. 11, No. 3, September 2002 ( C© 2002)

The Virtual Solar System Project: Developing ConceptualUnderstanding of Astronomical Concepts Through BuildingThree-Dimensional Computational Models1

Thomas Keating,2,6 Michael Barnett,3 Sasha A. Barab,4 and Kenneth E. Hay5

The Virtual Solar System (VSS) course described in this paper is one of the first attemptsto integrate three-dimensional (3D) computer modeling as a central component of an in-troductory undergraduate astronomy course. Specifically, this study assessed the changes inundergraduate university students’ understanding of astronomy concepts as a result of partici-pating in an experimental introductory astronomy course in which the students constructed 3Dmodels of different astronomical phenomena. In this study, we examined students’ conceptualunderstanding concerning three foundational astronomical phenomena: the causes of lunarand solar eclipses, the causes of the Moon’s phases, and the reasons for the Earth’s seasons.Student interviews conducted prior to the course identified a range of student alternative con-ceptions previously identified in the literature regarding the dynamics and mechanics of theSolar System. A previously undocumented alternative conception to explain lunar eclipsesis identified in this paper. The interviews were repeated at the end of the course in orderto quantitatively and qualitatively assess any changes in student conceptual understanding.Generally, the results of this study revealed that 3D computer modeling can be a powerfultool in supporting student conceptualization of abstract scientific phenomena. Specifically, 3Dcomputer modeling afforded students the ability to visualize abstract 3D concepts such as theline of nodes and transform them into conceptual tools, which in turn, supported the devel-opment of scientifically sophisticated conceptual understandings of many basic astronomicaltopics. However, there were instances where students’ conceptual understanding was incom-plete and frequently hybridized with their existing conceptions. These findings have significantbearing on when and in what domains 3D computer modeling can be used to support studentconceptual understanding of astronomy concepts.

KEY WORDS: computer modeling; conceptual change; astronomy; three-dimensional models; virtualreality.

1A previous version of this paper was presented at the 1999 annualconference of the American Educational Research Association inMontreal, Canada.

2The Tech Museum of Education.3Department of Curriculum and Instruction, Boston College, 140Commonwealth Avenue, Chestnut Hill, Massachusetts 02467-3813.

4Department of Instructional Systems Technology and CognitiveScience, School of Education, Indiana University, Bloomington,Indiana.

5Learning and Performance Support Laboratory, University ofGeorgia, Georgia.

6To whom correspondence should be addressed; e-mail: [email protected]

INTRODUCTION

Over a period of 3 years we developed andresearched an experimental, introductory under-graduate astronomy course as part of the VirtualSolar System (VSS) project. The VSS project lever-ages emerging three-dimensional (3D) computer-modeling technologies to establish a learningenvironment that supports students in collaborativeproblem solving through constructing models thatembody complex astronomical concepts (Barabet al., 2000a; Barnett et al., 2001a). Further, the VSSlearning environment is consistent with a social

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262 Keating, Barnett, Barab, and Hay

constructivist pedagogical framework in which therole of the teacher shifts from one of telling studentscorrect answers to supporting students in completingtheir activities and reflecting upon their evolvingunderstanding throughout the course (Bednar et al.,1992). Within this environment teams of studentswrestle with the conceptual complexity of astronomyby constructing shareable artifacts (in this casemodels) to investigate and demonstrate particularastronomical concepts (i.e. when and where do lunareclipses occur?). This study is one in a number ofstudies designed to develop an understanding ofhow emerging technologies can be used to supportstudents in learning science and how the construc-tion of computational models facilitate conceptualunderstanding of scientific phenomena (Barab et al.,2000a,b; Barnett et al., 2001b). In this paper, we focuson the conceptual understanding that students de-veloped through their participation in a summer VSScourse. Specifically, we examine students’ conceptualunderstanding concerning three foundational astro-nomical concepts: lunar and solar eclipses, phases ofthe Moon, and the reason for the Earth’s seasons.

BACKGROUND

Historically, scientists and educators have usedcomputational models to investigate and explorecomplex systems and phenomena. Only recently havethe tools that practicing scientists use to build compu-tational models intended to visualize complex con-cepts and phenomena been advanced as tools to helpstudents learn science (Edelson et al., 1999). Thisis due, in part, because educators have recognizedthat model-based reasoning can facilitate the develop-ment of mathematical-scientific understanding of thenatural world (Lehrer et al., 1994; Penner et al., 1998;Sabelli, 1994). Further, the growing power of com-puters, coupled with a reduction in cost and the avail-ability of inexpensive or free modeling software, havecreated opportunities to engage students in scientificinquiry through constructing computational modelsof scientific phenomena (Sabelli, 1994). For example,students can examine and explore basic physics byconstructing kinetic models using the ThinkerToolssoftware package (White and Frederikson, 1998),construct models that represent the factors that influ-ence ecosystems and water quality (Stratford, 1997;Stratford et al., 1998), and build computational mod-els of molecules (Kozma, 1999), to name just a few

of the groundbreaking projects being enacted in K-16settings. To date, these and most other modeling initia-tives have focused on engaging students in interactingwith or constructing two-dimensional (2D) models topromote the development of sophisticated levels ofconceptual understanding of scientific phenomenon.

There is a growing research base that claims thatstudents need to be able view and interact with phe-nomena in three dimensions because it is difficultfor students to transform 2D objects into 3D ob-jects, which is required for deep conceptual under-standing of many scientific concepts (Gotwals, 1995;Windschitl et al., 2001). Educators have begun to ex-plore the power of 3D technologies to support stu-dents in constructing models to visualize and under-stand scientific phenomena ranging from exploringweather cells (Hay et al., 2000b) to modeling gorillabehavior (Hay et al., 2000a). The emergence of 3Dcomputer modeling technologies is particularly cru-cial for the teaching and learning of astronomy. Manyastronomical concepts require students to develop anunderstanding of dynamic relationships and eventsthat occur in 3D space (Parker and Heywood, 1998).In fact, over 100 research studies have been con-ducted that report on the difficulty that students havein developing understandings of astronomical phe-nomena (Pfundt and Duit, 1998). In general, thesestudies have reported that students typically have im-poverished or contrary explanations of astronomicalphenomenon that present barriers to the adoptionof explanations currently accepted by the scientificcommunity (Barnett and Morran, in press; Sneiderand Ohadi, 1998; Treagust and Smith, 1989). For ex-ample, over the course of three semesters, Comins(1993) identified 553 separate alternative conceptionsexpressed by students in his introductory undergrad-uate astronomy courses. In another example, in thefilm A Private Universe (Pyramid Film & Video, 1988)only 2 of 23 recent Harvard graduates and alumniselected at random were able to provide a satisfac-tory scientific explanation for the causes of the Earth’sseasons. Similarly, Atwood and Atwood (1996) foundthat 39 of 42 preservice elementary teachers held al-ternative conceptions in regard to the causes of theEarth seasons.

Parker and Heywood (1998) hypothesized that3D technologies or 3D models could be used to sup-port students in developing scientific understandingsof astronomical phenomena. However, most resour-ces available to students are in the form of 2D chartsand images in textbooks, which attempt to emulate

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Understanding Astronomical Concepts Through Building 3D Computational Models 263

astronomical phenomena from different 3D perspec-tives (Barab et al., 2000a). Additionally, students haveonly one perspective in which to develop their under-standing of astronomy concepts—namely from theEarth’s perspective. The 3D models and manipula-tives historically available to educators (for exam-ple the Orreries found in a majority of science class-rooms) may not engage students in the kind of conceptbuilding activities necessary to promote conceptualchange. As a result, developing learning activities thatafford students the opportunities to examine astro-nomical phenomena from different perspectives hastraditionally been difficult because students simplycannot visit the Moon and look back at the Earthto observe the effects of the change in their perspec-tive (i.e. Does the Earth have phases when viewedfrom the Moon? Why?). Based upon this belief andthe results from previous research on student un-derstanding of astronomy, we set out to develop acourse in which students could construct models us-ing 3D computer modeling tools to develop rich con-ceptual frameworks for understanding the complexdynamics associated with the Solar System.

COURSE OVERVIEW

The Virtual Solar System (VSS) is a learner-centered, project-based (Blumenfeld et al., 1991), un-dergraduate astronomy course in which students workin dyads and triads, to build models of different as-pects of the Solar System. This structure is a shiftaway from traditional means of teaching astronomy.Typically, students are required to read or study de-scriptions of 3D concepts usually embedded within a2D format, such as a textbook or computer screen,and then visualize the 2D image as a 3D system(Parker and Heywood, 1998). However, developingan understanding of an inherently 3D concept froma 2D diagram or image is a challenging task formany students (Copolo and Hounsell, 1995; Khoo andKoh, 1998). Until recently, being able to model in3D meant gaining access to expensive computerworkstations with sophisticated visualization soft-ware. However, in the VSS course students construct3D virtual models on average computers using a free-ware software product and go beyond flat, limited2D images (e.g. charts, graphs) to build their own com-plex 3D models.

The curriculum for the course is comprised ofthree modeling projects of increasing complexity de-

signed to engage students in modeling various astro-nomical phenomena that are typically covered in atraditional lecture-based class (see Barab et al., 2000afor a detailed description of the course design andstructure). The first project consists of the studentsconstructing a 3D static model of the Celestial Sphere.The Celestial Sphere is a useful concept because it al-lows for the representation and visualization of thelocation of visible stars and important positions ofthe Sun throughout the year in relation to the Earth.The primary goal for the students during this projectis to construct a Celestial Sphere model which, in turn,supports the students in learning essential astronomi-cal terminology (e.g. right ascension, declination, andmeridian), the causes for the Earth’s seasons, and thelocation of the equinoxes and the solstices. In addi-tion, this first project serves as a vehicle to increasethe students’ comfort level with their computers, andto familiarize the students with the basic functionalityof the modeling software.

The second project consists of students construct-ing a 3D dynamic model of the Earth–Moon–Sun sys-tem. In this project, the students investigate the rela-tionships between the orbital paths, periods, distancesbetween, and rotational rates of the Earth, Moon,and Sun. This project builds on the conceptual rich-ness of the first project because students construct amodel with correct relative scale in size and distance,model the orbital motions of the three bodies, and in-vestigate with the dynamics of the Earth–Moon–Sunsystem. In addition to examining the dynamic rela-tionships of the Earth–Moon–Sun system, studentsalso compare their model with the real Earth–Moon–Sun system and report on any discrepancies (e.g.scale, orbital speeds) between the two. Lastly, studentsare asked to consider the differences and similaritiesof the interior structures of the Earth, Moon, andSun and demonstrate these differences through theirmodels.

The final project consists of students construct-ing a 3D dynamic model of the entire Solar System.Students are expected to build a model of the SolarSystem that takes into account the rotational and rev-olution rates of the planets, and the relative size anddistance between the planets. In constructing theirmodels students need to come to terms with the dif-ficult concept of the vast scale of the solar system.Lastly, similar to the second project, the students areasked to investigate the similarities and differencesbetween the planets’ orbital motions, spins, interiors,Moon systems, and atmospheres.

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MODEL CONSTRUCTION TOOLS

Students constructed their models using a VirtualReality Markup Language (VRML) editor. VRMLis similar to HTML in that it is the standard lan-guage used for viewing VR on the World Wide Web.VRML is platform independent, object oriented, andis easily viewed over the Web using a free plug-inand a web browser (student work can be seen athttp://vss.crlt.indiana.edu). The ease of porting stu-dents’ VRML projects to the Web is a large moti-vating factor for the students because they are awarethat their models can be viewed by their peers andcritiqued by anyone who has Web access.

Rather than writing cryptic VRML code, withsyntax similar to C++, students use CosmoWorlds, awysiwyg (what you see is what you get) VRML editordeveloped by CosmoSoftware, to construct theirmodels. CosmoWorlds reduces the tedious process ofcoding VRML to a few mouse clicks. For example,the code to construct and texture a sphere to look likethe Earth is over 10 lines of code in length. Insteadof typing in obscure commands, one simply dragsa sphere from the toolbox into the workspace andresizes it with a sizing tool. This procedure takes thestudent a few seconds and a few mouse clicks, freeinghim or her to concentrate on learning astronomyinstead of struggling to learn the syntax and structureof object-oriented programming.

THIS STUDY

In this study we examined the conceptual under-standing of eight students enrolled in the VSS courseduring a 1998 summer session. Seven of the eight stu-dents were typical introductory astronomy students.That is, they varied in technological and scientific ex-pertise and interest level in astronomy (and sciencein general). Six were nonscience majors. Our first re-search question focused on whether students build-ing 3D models of the Solar System show significantgains in understanding astronomy concepts. The sec-ond research question focused on what type of con-ceptual understanding does 3D modeling facilitate.In accomplishing these goals we conducted pre- andpostinterviews focusing on basic fundamental astro-nomical concepts.

Students and Teams

During the first week of the course, the eightstudents enrolled in the course divided themselves

into three separate teams. The teams were formedbased upon proximity, that is, the students that wereseated closest to each other formed a team. In whatfollows, we will briefly describe the makeup of eachteam and the scientific and technological backgroundof each team member to contextualize the class forthe reader.

Team Alpha

Team Alpha consisted of three male members:John, Jason, and Ryan. They entered the course withlarge disparities in their computer experience and sci-ence background. Ryan, a computer science major,entered the course with good computer skills, butminimal astronomy knowledge. Ryan reported thathe had distaste for science and had tried to take aslittle science as possible throughout his academic ca-reer. He enrolled in the class only to satisfy a sci-ence requirement. Jason, a history major, enteredthe course with average computer skills, but very lit-tle astronomy background knowledge. Unlike Ryan,Jason expressed a genuine interest in learning aboutastronomy. Jason also enrolled in the course to satisfya science requirement. John was a unique member ofthe class due to his status as an upperclassman and hismajoring in physics. He entered the course with con-siderable astronomy knowledge and good computerskills.

Team Beta

Team Beta consisted of two students: Paul andMary, both Telecommunications majors. Paul beganthe course with modest astronomy knowledge andaverage computer skills. Paul reported that the pri-mary reason he enrolled in the course was to learnabout the VR software, though he also had an inter-est in learning more about astronomy. Mary beganthe course with little background astronomy knowl-edge and very little computer knowledge comparedto Paul. Both Paul and Mary enrolled in the course tosatisfy a science requirement.

Team Gamma

Team Gamma consisted of three students: Lisa,Sally, and Keith. Lisa, a theater major, reportedthat she had a strong background in science andwas interested in deepening her understanding of

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astronomy. Complementing her astronomy knowl-edge, Lisa also was an experienced computer user.Sally, a biology major, did not have a background inastronomy, but reported that she had taken a begin-ning physics course and was interested in learningabout astronomy. Unlike Lisa, Sally had very littlecomputer experience. Keith, a returning student andundeclared major, had a strong interest in sciencebut very little background in astronomy. Similarto Sally, Keith also had relatively little computerknowledge.

METHODS

Data Collection

The students were interviewed twice, once at thebeginning of the course, and once immediately fol-lowing the completion of the course. The interviewquestions were semistructured, consisting of ninequestions that covered a wide range of astronomy con-cepts typically covered in the traditional introductionto astronomy courses. We also collected and examinedstudent papers and reflections and used these docu-ments to triangulate with our interview data. In thispaper, we focus on two questions that explore basic as-tronomical concepts and represent the strengths andlimitations of 3D modeling in supporting student con-ceptual understanding. The questions were derivedfrom the alternative conception research (Comins,1993; Sadler, 1996; Schoon, 1993; Treagust and Smith,1989; Vosniadou, 1991), and from consultation withfaculty members from the Astronomy Department atIndiana University, Bloomington. The questions thatare the focus of this paper are

1. Eclipses and phases: Can you draw the posi-tion of the Earth, Moon, and Sun when wecan see a Full Moon, New Moon, and a lunareclipse from the Earth? Describe the differ-ences and similarities between a Full Moonand a lunar eclipse.

2. Reasons for the seasons: What causes the sea-sons of the Earth? Draw a diagram that showsthe different seasons.

The preinterviews were conducted during thefirst 2 days of the class and videotaped to capturestudents’ conceptual understanding prior to theirconstructing 3D models. The preinterviews exam-ined the ability of students to explain and articulatetheir understanding of astronomy and to identify the

prevalence of alternative frameworks. The preinter-views typically lasted 15–30 min. The students wereasked to express their understandings verbally andprovided with a set of spheres for manipulation anda white board for drawing diagrams to demonstratetheir explanations. The interviewer asked probingquestions to establish the depth of students’ concep-tual understanding.

The postinterviews were videotaped and con-ducted during the last week of the course. Interviewstypically lasted 30–60 min. Again, the students wereasked to express their understandings either verballywhile manipulating spheres, or by drawing on theavailable white board. Our primary goal in evaluat-ing the interview responses was to assess student con-ceptual understanding concerning astronomical phe-nomena, with an emphasis on identifying instanceswhere students referred to their 3D models to ex-plain or supplement their understanding of astronomyconcepts.

Data Analysis

We assessed student conceptual understandingby extensive viewing of the videotapes, analysis andcoding of the transcribed interviews, and scoring thestudent responses by a rubric. The rubric is basedupon the categorization scheme used by a num-ber of researchers (Barnett and Morran, in press;Muthukrishna et al., 1993; Simpson and Marek, 1988).Both the pre- and postinterview responses werescored using a rubric adapted to the question of in-terest (see Tables I and II).

Both the course instructor and a researcher/interviewer scored every pre- and postinterviewquestion with the rubrics (Tables I and II). A cor-relation analysis was performed to determine thelevel of interrater reliability. The level of agreementfor Question 1 (eclipses) was rpre = 0.94 and rpost =0.96, Question 2 (seasons) was rpre = 0.90 and rpost =0.96.

RESULTS

The results section is divided into two sections.The first section reports on student conceptual un-derstanding with respect to eclipses and phases. Thesecond section reports on student conceptual changewith respect to the reasons for the seasons. That is,we present the students’ understanding prior to the

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Table I. Rubric Used to Evaluate Question 1 (Eclipses and Phases)

Score Category Response

0 No conception Students are unable to articulate a response to the question.1 Confused Students confuse the positions of a full Moon, new Moon, and lunar eclipse. Students have an

alternative framework. Students lack knowledge of basic concepts (Moon’s orbital tilt, rotationand revolution rates), and proper terminology (e.g., line of nodes, ecliptic).

2 Incomplete/inaccurateunderstanding

Students know the basic concept that the Moon’s orbit is tilted at 5◦, but do not discuss the line ofnodes or its importance for lunar eclipses. Students can point out the positions of a lunareclipse and solar eclipse, but struggle to articulate the difference between a full Moon andlunar eclipse.

3 Partial understanding Students know the basic concept that the Moon’s orbit is tilted at 5◦, but do not discuss the line ofnodes or its importance for lunar eclipses. Students can point out the positions of a lunareclipse and solar eclipse, but struggle to articulate the difference between a full Moon andlunar eclipse.

4 Completeunderstanding

Students understand the importance of the 5◦ orbital tilt of the Moon. They know about theecliptic and the Moon’s orbital plane, and that when these two planes intercept they form theline of nodes and that when the Earth, Sun, and Moon is on the line of nodes an eclipse occurs.Further, the students can point out the positions of a lunar eclipse and a solar eclipse, and canarticulate the difference between a full Moon and lunar eclipse.

course and then present the students’ conceptual un-derstanding at the conclusion of the course in regardto each astronomical phenomenon.

Eclipses and Phases

Preinterviews

In the preinterviews, two of the eight students,John and Lisa, demonstrated a partial understand-ing of the phases of the Moon and the causes ofeclipses (see Table III). Both students attributed thedifference between the two phenomena as having to

Table II. Rubric Used to Evaluate Question 2 (Eclipses and Phases)

Value Category Response

0 No conception Students are unable to articulate a response to the question.1 Confused Students do not know that the Earth is tilted, but have alternative conceptions, and lack

the proper terminology to articulate their limited understandings. When probedstudents provide contradictory and incorrect responses.

2 Incomplete/incompleteunderstanding

A student only expresses understanding that the Earth is tilted. There is presence of analternative conception that is hybridized in the students’ responses. For instance, thestudents may believe that summer occurs in the northern hemisphere when the Earth istilted toward the Sun, because the northern hemisphere is closer to the Sun.

3 Partial understanding The student recognizes the importance of the Earth’s tilt that it affects the angle ofincidence of Sunlight on the Earth and in turn effects the seasons, but are unable toelaborate on their response. There are no alternative conceptions present.

4 Complete understanding A student’s response demonstrates an understanding of the relationships between how thetilt of the Earth as it orbits the Sun effects the energy intensity of Sunlight on the Earth,and how the energy intensity is related to the seasons in the northern and southernhemispheres. At this level students have obtained a robust scientific perspective for thecause of the seasons.

do with the tilt of the Moon’s orbital plane, but couldnot articulate the significance of the Moon’s tilt.

Three students recognized that the Earth, Moon,and Sun have to line up to produce a lunar eclipse, butwhen probed could not explain why a lunar eclipsedoes not occur every month. Paul’s preinterview re-sponse demonstrates his incomplete understandingof the difference between a full Moon and a lunareclipse.

I: So how do we get a full Moon in the SouthernHemisphere?

Paul: As the Earth turns it turns into it. I guess onlythe position of the Sun and the Moon matter.

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Table III. Student Performance on Pre- and Postinterviews With Respect to Question 2: Eclipses and Phases

Student Pretest Pretest category Posttest Posttest category Total change Total possible change

Jason 1 C 4 CU 3 3John 3 PU 4 CU 1 1Ryan 1 C 2 IU 1 1Keith 2 IU 4 CU 2 2Lisa 3 PU 3.5 PU/CU 0.5 1Sally 1 C 3 PU 2 3Mary 1 C 4 CU 3 3Paul 1.5 C/IU 4 CU 2.5 2.5

Average 1.7 C/IU 3.60 PU/CUSD 0.88 0.73

Note. CU = complete understanding; IU = incomplete understanding; PU = partial understanding; C = confused;NC = no conception.

I: So how do we get a lunar eclipse?Paul: A lunar eclipse is?I: A lunar eclipse is when the Moon becomes dark

and bright again.Paul: We would need to get the Sun’s rays blocked. As

the Moon circles behind the Earth, the Moonmoves into the Earth’s shadow. So the full Moonis all bright and an eclipse is when the Moon isdark. The Moon is lined up with the Earth andSun.

I: So why don’t we get a lunar eclipse everymonth?

Paul: Lots of little things occur. Everything has to beperfect.

The remaining three students lacked a rudimentaryunderstanding of the Earth, Moon, and Sun sys-tem. This is evidenced by Jason’s confusion with thecause of lunar eclipses and phases in the followingsequence.

I: When do we get a lunar eclipse?Jason: I think it has something to do with the day

night sequence. I guess that when the Earth isturning, we see different sides of the Moon.

I: Okay, Does the Moon have phases?Jason: I’m trying to think why the Moon does that. I

am going to say yes. This is a complete guess. Ithink it is all a matter of perspective. It mighthave to do something with the rotation of theEarth. I would say yes.

Jason, similar to Paul, appears to holds the alternativeconception that lunar eclipses and phases are causedby the rotation of the Earth.

The preinterviews also revealed a previouslyunidentified alternative conception concerning the

spatial location of the Moon in its full phase. Threestudents believed that the Moon needed to be lo-cated to the side of the Earth in order for it to beable reflect the Sun’s light (see Fig. 1). Mary’s prein-terview responses are representative of this line ofreasoning.

I: So where does the Moon have to be to get afull Moon?

Mary: [Moving her spheres around]. I’m not surewhere it would be. Isn’t it that the Earth can’tcover any part of the reflection? When you seethe shadow on the Moon isn’t that the reflec-tion of the shadow of the Earth? I don’t knowwhere it would be.

I: Where would place the Moon sphere?Mary: Probably off to the side. So Sunlight can hit it.

We speculate that this alternative conception arisesfrom students’ difficulties in translating the typical2D representation of the Moon’s orbital motion thatthey see in most textbooks to 3D. Despite the highquality of many graphics in today’s textbooks it is stillquite difficult to represent the relative 3D spatial re-lationships between the Sun, Earth, and Moon on a2D textbook page. Additionally, it was also evidentthat the students were unaware that the Moon’s orbit

Fig. 1. Pictorial representation of students’ alternative frameworkconcerning the difference between a full Moon and lunar eclipse.

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is tilted 5◦ relative to the plane of the ecliptic, furtherconfusing the spatial relationships between the posi-tions of the Earth, Moon, and Sun.

Postinterviews

The postinterviews revealed that the studentsmade considerable gains in their understanding ofastronomy concepts related to the Earth–Moon–Sunsystem (see Table III). Generalizing across students,students developed a solid conceptual understandingof the reasons for eclipses and phases (χ2(4, 8) =5.85, p < 0.01) as their average score increased fromM = 1.69, (SD = 0.88) on the pretest to M = 3.56(SD = 0.73) on the posttest. In fact, five of the stu-dents developed a complete understanding, while twostudents developed a partial understanding accordingto our rubric. Only one student, Ryan, had an incom-plete understanding at the conclusion of the course.We attribute this to the way Ryan’s group, Team Al-pha, divided up the modeling tasks for Project 2. Ryantook responsibility for creating static models of the in-teriors and atmospheres of the Earth, Moon, and Sunat the expense of investigating the spatial and dynamicrelationships between the Earth, Sun, and Moonthat influence and cause eclipses and phases of theMoon. His teammates, Jason and John, constructedthe dynamic model of the Earth–Moon–Sun systemincluding orbital paths, tilts, and had more discussionsconcerning astronomy concepts that required anunderstanding of the 3D nature of astronomy.

Jason focused on constructing a model for histeam that would demonstrate the phases of the Moon.For instance, in Jason’s postproject paper he states thepurpose and his goals for his model.

The model’s purpose was to demonstrate the lunarphases from the Earth. However, the model coulddemonstrate just the opposite, too. In the center lies asmall sphere (Earth) and all around it lie even smallerspheres (Moon phases). As one can see, the Moongoes around the Earth in a circular plane.

That is, through building and exploring his 3Dcomputer model Jason developed a complete under-standing. Specifically, Jason used his model to shifthis frame of reference or perspective from one ob-ject to another and to examine the astronomical phe-nomenon of lunar phases from multiple perspectives.This ability to shift one’s frame of reference in 3Dspace is crucial to developing a deep understandingof astronomical concepts because a number of astro-nomical concepts can best be understood by viewing

objects from a different perspective (i.e. the differ-ence between synodic and sidereal time). Later in hispaper Jason discusses how he uses different referenceframes in his model to demonstrate why we see thephases of the Moon.

Our model shows that we cannot see the Moon whenit is in its new phase because it is receiving the Sun’srays on the side opposite of our view from Earth. Ifwe were standing on the Sun, we would be able to seea Full Moon. On the other hand, we can see the Mooncompletely at Full Moon because it is on the oppositeside of the Sun. It appears to us in full because it isreceiving the Sun’s rays relative to where we can seefrom the Earth.

Jason goes on to explain how his team’s model can notonly demonstrate the phases of the Moon, but alsohow his teams complete model could demonstratewhen solar and lunar eclipses occur.

However, when my model was combined with John’smodel we can see that, every so often, the Earth,Moon and Sun fall in a perfect or semi-perfectstraight line (usually semi-perfect) at the New Moonand Full Moon phases. At new Moon we have a solareclipse and Full Moon we have lunar eclipse. In bothcases, the three objects lines up because the eclipticand the Moon’s rotational plane intersect at a placecommonly called the line of nodes which we show inour model as a long thin cylinder.

Jason’s team employed their model to examinethe causes of the phases of Moon. Jason also used themodel to change his frame of reference from the Earthto the Sun and back again to simulate the relativespatial positions of the Earth and Moon in such a wayas to make it easier to visualize where the Moon iswhen it is in a particular phase. Further, their modelallowed Jason to represent abstract concepts such asthe line of nodes as a physical construct that could beused as a conceptual tool in his model to demonstratewhen eclipses occur. That is, the line of nodes wastransformed from simply a concept to be memorizedto a useful visual aid in supporting Jason in developingan understanding of spatial relationships that mustexist between Earth, Moon, and Sun to produce lunarand solar eclipses.

In his postinterview statement nearly 5 weeks af-ter Jason had finished his model on the Earth–Moon–Sun system Jason still applied the line of nodes andthe Moon’s orbital tilt as visual conceptual tools toexplain his understanding of the Earth–Moon–Sunsystem and eclipses.

I: So when do we get an eclipse?

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Jason: The Moon is going around the Earth and theMoon is behind the Earth, and the Earth isgoing around the Sun. The ecliptic and the ro-tational path intercept at the line of nodes anddue to the 5-degree tilt they cross at certainpoints. If it is a total eclipse, that is, it is an um-bral eclipse, it is beet-red. If it is penumbraleclipse, then it is partial eclipse. It depends onwhen the Moon is on the line of nodes.

I: You said the Moon is 5 degrees above or below,can it be anything different?

Jason: Yes, it has to be. That explains the differencebetween the umbral and penumbral eclipse. Soit has got to be. It also depends on where youare standing [pointing to his Moon’s location]to see the shadow.

Similar to Jason, Keith developed a mental modelthat called upon the 3D characteristics of his com-puter model. For instance, Keith refers to the Moonbeing above or below the Earth’s orbital plane in ex-plaining the difference between a full Moon and lunareclipse

I: Draw or show me the Earth, Sun, Moon con-figuration in the following phases, full Moon,and lunar eclipses.

Keith: When the Moon is behind the Earth and theMoon is in the umbra we have a total lunareclipse. However, if the Moon is in the Earth’spenumbra we don’t have a total eclipse. It isa partial eclipse. That is the Moon is in thePenumbra so it is partially shadowed. They arenot very noticed because there is not enoughof the Sun’s light blocked out. Now for a fullMoon. Now due to the Moon’s five degree tiltthe Moon is above and the Earth’s plane and isnot blocked by the Earth. It has to be furthestout to get a full Moon.

I: What are the differences and the similaritiesbetween full Moon and lunar eclipse.

Keith: For a lunar eclipse the Earth, Sun and Moon iscompletely aligned, which means it matcheswith the line of nodes which is where theMoon’s orbital plane and the ecliptic inter-sect each other. For a full Moon the tilt of theMoon’s orbit causes it to be higher or lower sothat the Sun’s light can hit it.

The active engagement of the students in mod-eling the system in three dimensions forced themto confront the often-overlooked phenomena of theMoon’s orbital tilt and the abstract concept of the

line of nodes. Rather, than being a useful fact to bememorized for an exam, the line of nodes became acentral component of all the models constructed bythe students. Specifically, the inclusion of the line ofnodes allowed the students to visualize when a lunareclipse would occur because students’ could includea visual representation of the line of nodes in theircomputer models. Perhaps most importantly, studentsabandoned the alternative conceptions they broughtwith them to the course for a sophisticated and scien-tifically accurate conceptual model of lunar eclipses.Traditionally, the concept of the line of nodes is a topicreserved for more advanced astronomy courses be-cause it is difficult for students to visualize the inter-section of 2D (i.e. the ecliptic and the Moon’s orbitalplane) planes in 3D space. However, in the contextof the VSS course, it became a conceptual tool forbuilding a model that accurately portrayed when andwhere eclipses occur because it provided a valuablereference point in 3D space that students could useto determine when eclipses occur. Even John, oneof only two students to identify the importance ofthe Moon’s orbital tilt in the preinterview, supple-mented his explanation with the concept of the line ofnodes.

What Causes the Seasons?

Preinterviews

Three quarters of the students entered the VRcourse with a range of common alternative con-ceptions regarding the seasons, similar to those re-ported in previous studies (Atwood and Atwood,1996; Comins, 1993). The preinterviews revealed thatthree students, Jason, Mary, and Paul, reasoned thatthe seasons are due to the rotation of the Earth. Twostudents, Ryan and Sally explained the seasons as afunction of the distance of the Earth from the Sun,and Keith believed the seasons were caused by thebouncing of light as it strikes the Earth’s surface as isrepresented in his preinterview response:

Keith: It sort of bounces off and it doesn’t have astraight focus as other locations on the Earth,so then it would be summer there. Lets turn itaround and look at June 21st. Now the Sun isgoing up and back, and the focus is here andlight is bounced off, the further you get awayfrom the focus is what causes the seasons. Thefurther away from the focus away from the Sunthe seasons occur.

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Table IV. Student Performance on Pre- and Postinterviews With Respect to Question 2: Reasons for the Seasons

Student Pretest Pretest category Posttest Posttest category Total change Total possible change

Jason 0 NC 4 CU 4 4John 2 IU 4 CU 2 2Ryan 1 C 2 IU 1 3Keith 1 C 2.5 IU/PU 1.5 3Lisa 3 PU 4 CU 1 1Sally 1.5 IU/C 2 IU 0.5 3.5Mary 1 C 2 IU 1 3Paul 2 IU 2 IU 0 2

Average 1.4 C/IU 2.8 PU/IUSD 0.90 1.00

Note. CU = complete understanding; IU = incomplete understanding; PU = partial understanding; C = confused;NC = no conception.

Only Lisa and John correctly attributed the phe-nomena of seasons to the 23.5◦ tilt of the Earth on itsaxis, however, they could not elaborate on the impor-tance of, or how, the tilt affects the incident energystriking the Earth’s surface. John, the upperclassmanand physics major, mistakenly explained the drop inaverage temperature during the winter months as dueto the scattering of shorter wavelength light in theatmosphere.

John: Yes, thickness of the atmosphere is very thin.So in the summer the light rays have less at-mosphere to travel through. Then in the winterthe light has to travel through more of the at-mosphere so you get a lower temperature.

I: Why does the temperature decrease?John: Well, because of light scatter for one thing, and

the shorter wavelength of light for example,blue light. The visual spectrum . . .So shorterwavelength is usually scattered and those arethe ones that are usually scattered. So they can’treach us and so the temperature is lower. So itis because the Earth . . . it is due to the Earth istilted.

Again, students struggled with explaining phe-nomenon that required an understanding of multiplevariables (incident light, tilt of the Earth, positionof the Earth and Sun) and how the relationships tothose variables interact in 3D space. For instance, theEarth’s tilt is actually constant at 23.5◦ and does notwobble through out the year, but that understandingis difficult to articulate without an appropriatevisualization of the phenomenon and without thatvisualization it is difficult for the average studentto successfully articulate the correct causes for theEarth’s seasons.

Postinterviews

In the postinterviews every student identifiedthe tilt of the Earth’s axis as the primary cause ofthe seasons. However, the modeling activities in thisproject did not prove as successful as the eclipsesand phases modeling activities. That said, the stu-dents still experienced gains in their conceptual un-derstanding (χ2(4, 8) = 5.85, p < 0.01). The studentsincreased their average score M = 1.4 (SD = 0.90)from the pretest to M = 2.81 (SD = 1.00) on theposttest. Table IV summarizes the results for the in-dividual students. Only two students, John and Lisa,elaborated their premodeling explanations to a com-plete understanding of why the Earth has seasons.

Two students, Sally and Ryan, developed hybridexplanation for the causes of the Earth’s seasons. Theycombined the correct idea of the tilt of the Earth onits axis with an alternative explanation they had ex-pressed in their preinterviews. In the initial phase ofthe postinterview, Sally and Ryan appeared to havemoved from the alternative conceptions expressed intheir preinterviews to an acceptance of the tilt as themajor cause of the seasons. However, on further prob-ing, both students were found to adhere to their alter-native frameworks in a hybrid-like relationship withthe tilt. In the quote below, Ryan articulates the re-lationship between the Earth’s tilt and the solsticesand equinoxes. However, when encouraged to elabo-rate on his understanding, his alternative conceptionof the seasons being related to distance reemerges inhis explanation.

I: So the first question is the classic what causesthe seasons of the Earth?

Ryan: What causes the seasons of the Earth, that’sthe . . . , partly because of the 23.5 degree tilt

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of the Earth and the way the Sun goes aroundit. (Picks up two spheres to demonstrate.) Al-right, it’s kind of tilted. Depending on wherethe Sun is at which equinox or, what is theword I’m looking for, solstice. Summer, Sum-mer Solstice, Autumnal Equinox, Winter Sol-stice, Vernal Equinox. That’s what causes theseasons. Different positions of the Sun at dif-ferent times and certain points, at least herein America and North America, the northernhemisphere, the Sun, although it is actually fur-ther away from the Earth at this time, the Sunis actually out longer, so that’s why it’s warmer.Then around here the Sun’s closer to the Earth.

I: What do you mean by further away and closer?Ryan: It’s um . . . It can’t be distance. That can’t be

right. I should remember further and closer.I: You can draw it too, whatever you like.Ryan: Oh, I just screwed myself up. I can’t explain it

any further. I just remember it being furtheraway in the summer and closer in the winterbut Sunlight is exposed longer to the Earth inthe summer and that’s why it is warmer.

Ryan’s team developed a model that had view-points at various locations on their model Earth fromwhich they could examine the location of the solsticesand equinoxes from different perspectives. However,this aspect of his 3D model did not appear to supporthis understanding concerning how the incident lightchanges when the Sun is at a solstice or equinox. Inaddition, Ryan persisted in describing the seasons tobe, at least partly, due to the distance of the Sun fromthe Earth. He also lacked a conceptual understandingof how the tilt affects the incidence of light per unitarea on the Earth’s surface. This is due, in part, tothe limitations of the modeling software, and again,possibly due to the tasks his team assigned to Ryanfor this project. Students were unable to easily modelthe incidence of Sunlight on the Earth’s surface intheir VR models. However, the intensity of the lightdid change on their model Earth depending on theposition of the Sun, but this 3D model did not ade-quately serve as a way to visualize why the Earth hasseasons.

In addition to software constraints, the organiza-tion of the modeling projects may have limited studentconceptual understanding. Some students appearedto confuse the fact that they developed multiple com-plex 3D models that served similar but slightly dif-ferent purposes. Keith, who at best obtained an in-complete understanding of the causes for the seasons,

experienced difficulties in distinguishing the astron-omy concepts being modeled in the first project onthe static Celestial Sphere to those modeled in thesecond dynamic project.

Keith: OK, causes of the season of the Earth. (Pick-ing up balls). I’m, trying to remember just howthe Earth revolves around, I still didn’t get allthis. I know that the Sun and the Earth areon the ecliptic. Earth has a 23 and 1/2 degreetilt. It goes around once a year. I even didthis on the first project, but I can’t rememberexact. . . .Oh! Here I’ll try to get a 23 1/2 de-gree tilt, but I thought there was also a tilt tothe ecliptic. I am getting so lost.

I: Feel free to editorialize as much as you want.Keith: Here’s my problem, the first project looked

like we had a tilt such as this. But when wewere making the last project it seemed likethey were on the same path, it’s just that theEarth was tilted. I know that the Earth has a23 1/2 degree tilt. I know it is just the way that,I’m still confused. It’s because of the way wedid our models.

We hypothesize that Keith is confused due tothe different frames of reference featured in the firstand second projects. Project 1, the Celestial Sphere, isbased on a static geocentric (Earth-centered) modelof the Solar System in which the Sun, and not theEarth, was tilted 23.5◦ relative to the Earth’s equato-rial plane. In contrast, in Project 2 the model of theEarth–Moon–Sun system is based on a dynamic, he-liocentric model in which the Earth displays its propertilt. In both projects Keith’s team used viewpoints toexplore their 3D model. A viewpoint is simply a vir-tual camera placed at a particular location in spacethat allows viewing of different portions of the stu-dents’ virtual world. In the first project, the teams’viewpoints were similar to the points of view demon-strated in the textbook, whereas in the second project,rather than imitating the book, the team chose theviewpoint positions to demonstrate many differentastronomical concepts. As evidenced by Keith’s state-ment, his confusion in trying to reconcile the two mod-els was an unanticipated outcome of structuring thecourse from the simplified, static, geocentric model atthe beginning of the course to the more complex, dy-namic, heliocentric models as the course progressed.Hence, in our redesign of the course we are abandon-ing the use of 2D textbook images and have developed3D models to be viewed and examined via the web tosupport students in doing their research.

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Despite the difficulties that some of the studentshad in developing an understanding of the reasons ofthe seasons, some students did develop a completeunderstanding of the reasons for the seasons. For ex-ample, Jason in his preinterview, when asked whatcaused the Earth’s seasons, responded

The way the Earth turns from East to West has to dowith Day and Night I think. In the diagram it talkedabout the tropic of Capricorn and tropic of cancer. Icouldn’t think of anything before starting the class. Ithink it has to do also with something how fast theEarth rotates, but I really don’t know.

In his postinterview, however, Jason responded with aconsiderably more detailed articulation of the reasonsfor the Earth’s seasons.

I: What causes the seasons of the Earth? Can youexplain it with the balls or can you Draw me adiagram?

Jason: I really don’t remember how I answered it mylast time here, I really didn’t have a good expla-nation. There’s two ways to look at it I guess;one, is the earth going around the sun at the23.5 degree tilt, but actually I think it is easierusing the celestial sphere model. The eclipticcan either be the earth going around the sun orthe sun going around the earth. I guess what itcomes down to is the Tropic of Cancer, Equa-tor, and Tropic of Capricorn, the summer sol-stice being at the highest point, or the zenith,and that’s when all of the sun’s light shines di-rectly on the northern, is that right? Yeah, itshines directly above the equator, how’s that?

I: And what do you mean by directly?Jason: Well, rather than just shine, it’s higher up. It

doesn’t beat around the bush. Like when it’s(the Sun) out here it casts a long shadow. Goshhow do I say it? It’s just right up there. The sunsrays are concentrated in that area.

Jason’s postinterview revealed that he had notonly developed an understanding of the reasons forthe Earth’s seasons, but also could use appropriateastronomical terminology to support his argument.Further, in his final paper describing his model Jasonexplains

In our model we put the Tropic of Cancer and Tropicof Capricorn as lines on our Earth and placed view-points so we could demonstrate that on the summersolstice and winter solstice the Sun is directly over-head if you are standing there at noon. Thus, ourmodel shows why the Earth’s has seasons, becauseon the first day of winter the Sun is over the tropic of

Capricorn which means that the Sun’s rays are hittingthe Northern Hemisphere less direct angle. However,in the southern hemisphere it is the first day of sum-mer because the Sun’s rays are striking much moredirectly than in the Northern Hemisphere.

Jason’s understanding of the reasons for the Earth’sseasons is reified through his model. That is, duringhis explanation Jason refers to how his team’s modeldemonstrates the Earth’s seasons and how his teamdesigned his model to demonstrate the Earth’s sea-sons. Therefore, Jason’s model is much more than asimple artifact, but is actually a visual reference thatsupports his development of a mental model that heuses to articulate his understanding of the Earth’sseasons.

DISCUSSION

The students that participated in the VSS coursedemonstrated significant gains in their conceptual un-derstanding concerning the cause of the Earth’s sea-sons, the reasons for the Moon’s phases, and whyeclipses occur. The 3D modeling environment ap-peared to be particularly effective in supporting stu-dent learning in two fundamental ways: (1) allowingstudents to construct 3D models that could be viewedfrom several different perspectives, and (2) support-ing students’ ability to visualize abstract concepts suchas the line of nodes and the Moon’s orbital tilt rela-tive to the Earth. In particular, the 3D modeling soft-ware allowed students to change their frame of refer-ence either by navigating through 3D space or throughthe use of viewpoints. This ability to easily shift theirframe of reference afforded each group the oppor-tunity to discuss where they should place themselvesin order to observe particular astronomical phenom-ena. For example, students placed viewpoints or po-sitioned themselves at various locations on or nearthe Earth to determine the spatial positions of theEarth, Moon, and Sun when an eclipse occurred intheir model (i.e. on the line of nodes). This naviga-tional ability afforded by the 3D computer modelingsoftware not only allowed the students to place them-selves in the role of the Earth, Sun, a third personobserver, or the Moon, but also provided them witha powerful tool to test and revise their models. Forinstance, students could quickly shift their position intheir model to test their evolving understanding. Thus,the 3D computer modeling environment enabled stu-dents to quickly and easily shift their frame of ref-erence and view their model from another perspec-tive and then examine whether their understanding

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holds when viewed from another perspective. This, inturn, supported students in understanding the causesof eclipses.

The 3D computer technology supported the stu-dents in visualizing abstract 3D concepts and helpedthem create representations that could be used as con-ceptual tools to assist them in developing and evolv-ing their understanding. For example, in Project 2 theconcept of the line of nodes emerged as a concep-tual tool which supported students in developing theirunderstandings of the differences and similarities be-tween a full Moon and a lunar eclipse. The conceptof the line of nodes is usually considered too difficultfor beginning astronomy students, and frequently re-moved from the curriculum. However, in the act ofmodeling the Earth, Moon, and Sun system, everystudent found the line of nodes to be central in help-ing them make sense of why and when eclipses occur.In other words, the 3D computer models supportedthe transformation of abstract 3D concepts (i.e. line ofnodes) into concrete objects that students could thenuse to construct and evolve their understanding.

The lack of student understanding of the role ofincident solar radiation on the Earth’s surface as themajor factor influencing the seasons was disappoint-ing, but understandable in hindsight. During the firstproject the students’ constructed static models thatsimply placed the Sun at the solstices and equinoxesin their model. Although extremely valuable fordeveloping an understanding of the location of theequinoxes and solstices, this model did not supportstudents in developing an appreciation for how lightfrom the Sun strikes the Earth. Subsequently, thestudents struggled to visualize how the incident lightchanges as the Sun’s altitude shifts during the courseof year and, subsequently, they were unable to ade-quately explain the causes of the seasons during thepostinterview. Thus, the 3D modeling environmentused in the course did not appear to be the optimumpedagogical tool for supporting students in devel-oping an understanding of the causes of the Earth’sseasons.

We acknowledge the limitations of the findingsreported in this pilot study of student learning in aVR astronomy course. The low class size of eight stu-dents may have had a significant positive effect onthe overall learning environment and group dynam-ics. Low class size facilitates greater opportunities forinteraction with the instructor and potentially greaterlearning outcomes. Further, we need a larger samplesize before we can generalize concerning when 3D vi-sualization tools might be most useful for supporting

student learning. However, this study does provideevidence that 3D technologies do have the potentialfor substantially improving student learning, particu-larly when students are asked to understand conceptspredicated on 3D spatial relationships.

IMPLICATIONS

Three-dimensional technologies create excitingopportunities for students to create, manipulate, andinteract with their own constructions which, in turn,supports them in developing understandings throughtheir first-hand experience—especially with respect toastronomy learning. For example, many students areasked to learn 3D astronomical concepts through theexamination and study of 2D images and graphs whichare difficult to interpret and harder to mentally visu-alize in three dimensions (Barab et al., 2000a). Unfor-tunately, it is typically left to the student to somehowabstract in their mind these 2D diagrams and imagesinto forms that make sense to them in 3D. To do thisrequires students to make intuitive leaps that are voidof any concrete attachment to previous experience(Walkerdine, 1997). As a result, students construct un-derstandings that are frequently in contradiction withcurrent scientifically accepted explanations (Pfundtand Duit, 1998; Wandersee et al., 1994). However, asdemonstrated in the VSS course, we now have thetechnological tools to assist students in visualizing ab-stract scientific phenomena in three dimensions. Forexample, the causes of eclipses cannot be adequatelyrepresented in a 2D format because the Moon is notin the same orbital plane as the Earth and the Sun, buttitled at an angle as it revolves around a rotating Earthwithin 3D space. Therefore, if we are to better supportstudents’ learning of astronomy it is necessary thatinstruction reflect this inherent spatial and dynamicalnature of astronomy. The results of this study are a firststep in developing an understanding of which partic-ular aspects of astronomy can best be taught throughthe use of 3D models and visualizations.

The incorporation of 3D modeling activities inscience courses also has the potential to facilitatestudent reevaluation of their alternative conceptions(Winn and Windschitl, in press). Conceptual changetheory requires that students first be dissatisfied withtheir existing conceptual understanding before mean-ingful change will occur (Posner et al., 1982; Strike andPosner, 1992). By engaging students in model build-ing activities they can quickly compare their existingunderstanding with their model and then reevaluatetheir understanding based upon feedback from their

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interactions with their model (Penner et al., 1998).This process is facilitated when students are providedactivities that engage students in direct experienceswith the concepts under study (Demastes et al., 1995;diSessa and Minstrell, 1998). For example, a 3D com-putational model allows students to construct a real-istic model that they can “step into” and shift theirframe of reference from one perspective to anotherwhich then affords multiple opportunities to examinetheir understanding from multiple perspectives. Thisis particularly important for astronomy education be-cause to understand why eclipses occur a student mustunderstand the revolution of the Earth, the Moon, andthe orbital paths of the Earth and Moon at a minimum.Therefore, if students can view the Earth–Moon–Sunsystem from different perspectives the likelihood thatthey will develop a scientifically accurate explanationis greatly enhanced because they can test if their un-derstanding holds from many different vantage points(i.e. is the configuration of the Earth–Moon–Sun thesame during a lunar eclipse when viewed from theEarth and the Moon?).

Emerging computer technologies, such as 3Dmodeling, provide students with the means to con-struct concrete representations of abstract conceptsthat are frequently poorly portrayed as 2D diagramsor simply described in textbooks (Windschitl et al.,2001). However, despite the potential that emergingtechnologies show in supporting student understand-ing, it must be kept in mind that 3D computationaltools may not be useful for all situations as demon-strated in the student difficulty concerning the rea-sons the Earth’s seasons. However, as a field we arejust beginning to explore how these new technolo-gies can support student learning. As these technolog-ical tools become more commonplace in K-12 settingswe must continue to examine the potential that thesetools have in not only supporting the development ofstudent understanding of scientific concepts but alsohow these tools might also lead to student misunder-standings (Winn and Windschitl, in press). It is ourhope that the study and findings presented here willhelp stimulate further investigations of the potentialfor increased science learning through 3D modelingin a variety of other science domains and educationalsettings.

ACKNOWLEDGMENTS

The authors thank the Virtual Reality/VirtualEnvironments Group at Indiana University,Bloomington, for their support in using the CAVE

Automatic Virtual Environment (CAVE). Theauthors also thank James G. MaKinster, Kurt Squire,and April Leuhmann for their comments on aprevious version of this paper.

REFERENCES

Atwood, R. K., and Atwood, V. A. (1996). Preservice elementaryteachers’ conceptions of the causes of seasons. Journal ofResearch in Science Teaching 33: 553–563.

Barab, S. A., Hay, K. E., Barnett, M., and Keating, T. (2000a).Virtual solar system project: Building understanding throughmodel building. Journal of Research and Science Teaching 37:719–756.

Barab, S. A., Hay, K. E., Squire, K., Barnett, M., Schmidt, R.,Karrigan, K., and Johnson, C. (2000b). Virtual solar systemproject: Developing scientific understanding through modelbuilding. Journal of Science Education and Technology 9:7–26.

Barnett, M., Barab, S. A., and Hay, K. E. (2001a). The virtual so-lar system project: Student modeling of the solar system. TheJournal of College Science Teaching 30: 300–305.

Barnett, M., MaKinster, J. G., and Hansen, J. (2001b). Exploringelementary students’ learning of astronomy through modelbuilding. Paper Presented at the Annual Meeting of the Amer-ican Education Research Association, April, Seattle, WA.

Barnett, M., and Morran, J. (in press). Addressing children’s’ un-derstanding of the Moon’s phases and eclipses. InternationalJournal of Science Education.

Bednar, A. K., Cunningham, D., Duffy, T. M., and Perry, D. J.(1992). Theory into practice: How do we link? In Duffy, T.,and Jonassen, D. (Eds.), Constructivism and the Technology ofInstruction, Erlbaum, Hillsdale, NJ, pp. 17–34.

Blumenfeld, P., Soloway, E., Marx, R., Krajcik, J., Guzdial, M.,and Palincsar, A. (1991). Motivating project-based learning:Sustaining the doing, supporting the learning. EducationalPsychologist 26: 369–398.

Comins, N. F. (1993). Sources of misconceptions in astronomy. InNovak, J. (Ed.), Proceedings of the Third International Confer-ence on Misconceptions and Educational Strategies in Scienceand Mathematics [distributed electronically], Cornell Univer-sity, Ithaca, NY.

Copolo, C. F., and Hounsell, P. B. (1995). Using three-dimensionalmodels to teach molecular structures in high school chemistry.Journal of Science Education and Technology 4: 295–305.

Demastes, S. S., Good, R. G., and Peebles, P. (1995). Students’ con-ceptual ecologies and the process of conceptual change in evo-lution. Science Education 79: 637–666.

diSessa, A., and Minstrell, J. (1998). Cultivating conceptual changewith benchmark lessons. In Greeno, J., and Goldman, S. (Eds.),Thinking Practices in Mathematics and Science Learning,Erlbaum, Mahwah, NJ, pp. 155–187.

Edelson, D., Gordin, D., and Pea, R. (1999). Addressing thechallenges of inquiry-based learning through technology andcurriculum design. The Journal of the Learning Sciences 8: 391–450.

Gotwals, R. R. (1995). Scientific visualization in chemistry, betterliving through chemistry, better chemistry through pictures:Scientific visualization for secondary chemistry students. InThomas, D. A. (Ed.), Scientific Visualization in Mathematicsand Science Teaching, AACE, Charlottesville, pp. 153–179.

Hay, K., Crozier, J., and Barnett, M. (2000a,). Virtual gorilla model-ing project: Middle school students constructing virtual mod-els for learning. Paper Presented at the Annual Meeting ofthe American Educational Research Association, April, NewOrleans, LA.

P1: FHD



Hay, K. E., Marlino, M., and Holschuh, D. R. (2000b). The vir-tual exploratorium: Foundational research and theory on theintegration of 5-D modeling and visualization in undergrad-uate geocscience education. In Fishman, B., and O’Connor-Divelbiss, S. (Eds.), Proceedings of the Fourth InternationalConference of the Learning Sciences, Erlbaum, Mahwah, NJ,pp. 214–220.

Khoo, G., and Koh, T. (1998). Using visualization and simulationtools in tertiary science education. Journal of Computers inMathematics and Science Teaching 17: 5–20.

Kozma, R. (1999). Students collaborating with computer modelsand physical experiments. In Hoadley, C., and Roschelle, J.(Eds.), Proceedings of the Computer Support for CollaborativeLearning (CSCL) 1999 Conference [On-line], Erlbaum,Mahwah, NJ. Retrieved from http://kn.cilt.org/cscl99/

Lehrer, R., Horvath, J., and Schauble, L. (1994). Developing model-based reasoning. Interactive Learning Environments 4: 219–231.

Muthukrishna, N., Carnine, D., Grossen, B., and Miller, S. (1993).Children’s alternative frameworks: Should they be directly ad-dressed in science education? Journal of Research in ScienceTeaching 30: 233–248.

Parker, J., and Heywood, D. (1998). The Earth and beyond: De-veloping primary teachers’ understanding of basic astronomi-cal events. International Journal of Science Education 20: 503–520.

Penner, D. E., Lehrer, R., and Schauble, L. (1998). Fromphysical models to biomechanics: A design-based model-ing approach. The Journal of the Learning Sciences 7: 429–449.

Pfundt, H., and Duit, R. (1998). Students’ Alternative Frameworksand Science Education, 5th Bibliography, Institute for ScienceEducation, Kiel University, West Germany.

Posner, G., Strike, K., Hewson, P., and Gertzog, W. (1982). Ac-commodation of a scientific conception: Towards a theory ofconceptual change. Science Education 66: 221–227.

Pyramid Film and Video (1988). A Private Universe [Film], AnInsightful Lesson on How We Learn, Pyramid Film & Video,Santa Monica, CA.

Sabelli, N. (1994). On using technology for understandings science.Interactive Learning Environments 4: 195–198.

Sadler, P. (1996). Astronomys conceptual hierarchy. In Percy,J. (Ed.), Astronomy Education: Current Developments, Fu-ture Coordination. Astronomical Society of the Pacific. SanFrancisco, CA, pp. 26–34.

Schoon, K. J. (1993). The origin of Earth and space science mis-conceptions: A survey of pre-service elementary teachers. In

Novak, J. (Ed.), Proceedings of the Third International Seminaron Misconceptions and Educational Strategies in Science andMathematics [distributed electronically], Cornell University,Ithaca, NY.

Simpson, W. D., and Marek, E. A. (1988). Understandings and mis-conceptions of biology concepts held by students attendingsmall high schools and students attending large high schools.Journal of Research in Science Teaching 25: 361–374.

Sneider, C., and Ohadi, M. (1998). Unraveling students’ misconcep-tions about the Earth’s shape and gravity. Science Education82: 265–284.

Stratford, S. J. (1997). A review of computer-based research in prec-ollege science classrooms. Journal of Computers in Mathemat-ics and Science Teaching 16: 3–23.

Stratford, S. J., Krajcik, J., and Soloway, E. (1998). Secondarystudents’ dynamic modeling processes: Analyzing, reasoningabout, synthesizing, and testing models of stream ecosystems.Journal of Science Education and Technology 7: 215–234.

Strike, K. A., and Posner, G. J. (1992). A revisionist theory of con-ceptual change. In Duschl, R. A., and Hamilton, R. J. (Eds.),Philosophy of Science, Cognitive Psychology, and EducationalTheory and Practice, State University of New York Press,New York, pp. 147–176.

Treagust, D., and Smith, C. L. (1989). Secondary students’ under-standing of gravity and the motion of planets. School Scienceand Mathematics 89: 380–391.

Vosniadou, S. (1991). Designing curricula for conceptual restruc-turing: Lessons from the study of knowledge acquisition inastronomy. Journal of Curriculum Studies 23: 219–237.

Walkerdine, V. (1997). Redefining the subject in situated cogni-tion theory. In Kirshner, D., and Whitson, J. A. (Eds.), Situ-ated Cognition: Social, Semiotic, and Psychological Perspec-tives, Erlbaum, Mahwah, NJ, pp. 57–70.

Wandersee, J. H., Mintzes, J. J., and Novak, J. D. (1994). Researchon alternative conceptions in science. In Gabel, D. L. (Ed.),Handbook on Science Teaching and Learning, Macmillan,New York, pp. 177–210.

White, B. Y., and Frederikson, J. R. (1998). Inquiry, modeling,and metacognition: Making science accessible to all students.Cognition and Instruction 16: 3–118.

Windschitl, M., Winn, W., and Headley, N. (2001). Using immer-sive visualizations to promote the understanding of complexnatural systems: Learning inside virtual Puget Sound. PaperPresented at the Annual Meeting of the National Associationfor Research on Science Teaching.

Winn, W., and Windschitl, M. (in press). Learning in artificial envi-ronments. Artificial Environments.

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