Educational Underpinnings of Lecture-Tutorials for Introductory Astronomy

Tim Slater, CAPER Center for Astronomy & Physics Education Research, tslater@caperteam.com  

Theories of Learning focused on the Student

It is all too often easy to forget that learning theories obviously or quietly influence what classroom environments look like. On one hand, theories of learning used in classrooms where the teacher is the expert source of all knowledge are known as TEACHER-CENTERED classrooms.  This is where the learning theory guiding the classroom put the teacher in the role to perform and present—perhaps download—information and ideas to the class.  Teacher-centered classrooms are focused on the performance and presentation of the teacher, and improving these classrooms focus on the teacher being the one to be making better presentations and better lectures with better illustrations, examples, and analogies.  On the other hand, classrooms could be focused on what students are doing every day instead of what teachers are doing. This perspective is in stark contrast to that of student-centered classrooms, or LEARNER-CENTERED teaching. Improvements in learner-centered classrooms instead focus on changing the student experience by having students talk about and sort out concepts, rather than being told what they should think and believe about scientific ideas.  Although it isn’t clear than one is always better than the other, what is certain is that learning theories driving the design and operation of learner-centered classrooms look very different.

A contrasting theory of learning that is more learner-centered is that of CONCEPTUAL CHANGE.  Widely advocated by US-based Peter Hewsen and his talented colleagues like Strike and Posner (1982, 1992) in the later Twentieth Century, conceptual change is based on the notion of teaching students who enter learning already holding ideas they have developed with considerable mental effort.  In response, it is the job of the teacher to build an environment that exposes students’ initial ideas, challenges the students’ thinking, and replaces the pre-existing astronomy ideas with new and better ideas.  Long-time physics education researcher Lillian Chris McDermott and her colleagues (2001) at the University of Washington (USA) describe teaching aligned with this theory of learning as elicit, confront and resolve. Clearly, classical conceptual change in astronomy teaching has an underlying commitment to the teaching philosophy of constructivism, as briefly described above.

For a teacher who subscribes to conceptual change as a theory of learning, a teacher’s job is to find and help students replace their astronomy misconceptions with scientifically accurate ideas.  Whereas a positivist instructor would hold the position that simply telling students that they have a misconception and that the correct ideas should over-write the incorrect ideas, a teacher subscribing to conceptual change believes that new ideas will only be considered if there is dissatisfaction with old ideas. Moreover the newly proposed ideas have to be completely understandable and be able to better explain a wider range of ideas than the old ideas for conceptual change to successfully apply.

Early classroom applications of conceptual change were focused on using a three-phase learning cycle, advocated widely by Karplus and Butts (1977).  The first phase of such a learning cycle is exploration were students wrestled with a phenomena or observation that was unexpected, known in education circles as a decrepit event, and presented to astronomy students without an explicit agenda revealed by the teacher.  Some example decrepit events in astronomy teaching might be: (a) if it is hotter in the summertime because we are close to the Sun, why might the northern and southern hemisphere seasons be reversed?; (b) if our Moon has no gravity, how did astronauts successfully walk on our Moon?; (c) if planets spin more slowly the farther they are from the Sun, why might Jupiter spin faster than Saturn?; (d) if main sequence stars move on the HR diagram toward the right when they run out of useable fuel in their core, just where might they move to in outer space?; and (e) if we can determine which direction our galaxy is moving in an evolving Universe by looking for redshifts in one direction and blue shifts in the opposite direction, what might it mean if we observe red shifts in all directions?.

The second of the three phases in the classical learning cycle is that of concept introduction.  In this phase, astronomy teachers are to tie the descript event to the scientifically accurate idea, usually through a didactic, lecture-based strategy.  It is in this phase where students are introduced to the accurate scientific vocabulary that better describes the ideas they wrestled with in initial the exploration phase. This cycle is then closed by a third phase known as concept application, where students are to practice applying their new thinking in novel applications. Taken together, a teaching practice aligned with this theory is to repeatedly have students engage with phenomena and come to a more meaningful understanding.

In the decades following Karplus, this three-phase approach has been expanded to a five-phase approach.  Advocated by US science educator Roger Bybee (2002), who was then working in the domain of Biology Education, the 5E approach has gained favor among teachers and curriculum developers.  The 5E approach phases are Explore, Engage, Explain, Extend, and Evaluate.  Whether a teacher thinks the better teaching practice here is to use a 3-phase or a 5-phase, or even a 10-phase learning cycle, the underlying theory here is that students will better learn an astronomical concept if they have targeted and repeated engagements with the idea, rather than a single, isolated experience.  Where these student-centered learning phases starkly contrast from the teacher-centered information download practice of teaching is that students’ initial ideas are taken to be serious and influential parts of the learning process and purposeful mechanisms exist to include, alter, and extend students’ thinking.

In recent years, conceptual change theory has been more serious modified to include students’ attitudes and motivation for learning.  The changes in conceptual change theory are due in large part, to a broad failure for conceptual change learning cycles to work with emotionally-laden topics.  Astronomy teachers using conceptual change have often noticed that providing students with discrepant events and data intended to cause internal cognitive conflict driving conceptual change in particular domains had little to no impact.  Most notably, the astronomy topics seemingly largely immune to conceptual change were: astrology as influencing human events, Big Bang Theory of the creation of universe (Prather, Slater, Offerdahl, 2002), the Expanding Universe, evolution of planetary atmospheres as a result of biological evolution, and anthropogenic (human-caused) planetary climate change, among others.  In other words, in the practice of teaching through conceptual change, no amount of data or logical argumentation seemed to alter some students thinking about such issues.  In response, parts of conceptual change theory have been altered to account for emotionally-laden issues where students’ self-identity is threatened by a particular scientific idea.  Known widely as “hot” conceptual change theory, the teaching practice that shows some promise for enhancing student’s thinking in these domains is one of having students evaluate the thinking of other people from afar, perhaps as case studies or consideration of mini-debates among other people, rather than engaging the students’ own thinking.  The underlying idea is that students will more readily evaluate the thinking of others than themselves.  Such practices are seen as less risky to students’ self-identity and allow for a considerate teacher to more respectfully present and challenge opposing points of view.  (For more on this hot conceptual change, see work by US science educator Doug Lombardi and his colleagues (2010) in this domain.)

Lecture-Tutorials for Introductory Astronomy: An Instructional Strategy In-between a Teacher-Centered and a Student-Centered Approach.  To take advantage of students’ needs to have guided and extended experiences in understanding a new idea, Jeff Adams and Tim Slater, then at Montana State University in the US, led a team developing a series of instructional materials called LECTURE TUTORIALS FOR INTRODUCTORY ASTRONOMY (Prather, Slater, Adams & Brissenden, 2004 & 2012).  Lecture Tutorials were designed to combine the advantages of SOCRATIC DIALOGUE teaching approaches with the collaborative activity benefits from THINK-PAIR-SHARE.

Lecture-Tutorials are carefully designed worksheets that students collaboratively complete in pairs.  Each worksheet takes 10-15 minutes to complete and is used during class time after a short lecture to help students extend their understanding and demonstrate the power of astronomy models.  Upon inspection, the questions posed on the worksheets are similar to the series of questions a considerate teacher might ask a struggling student if they were tutoring the student in a one-on-one face-to-face setting after class.  In this way, Lecture-Tutorials are designed to move students from a novice understanding of an idea to a more comprehensive understanding (Brogt, 2007).

A strategy highly characteristic of these worksheets is to ask students to evaluate a conversation between two students.  Often described as a MINI-DEBATE (see Slater, 2010), the worksheets provide a short quoted dialogue between two students.  For example, one student might be portrayed as saying to another student, “the Moon has not water because it has no gravity” who then responds by saying, “The Moon does have gravity, like any other planet, and the Moon’s water is frozen as un-melted ice in deep craters that never are exposed to sunlight.”   The learners using the Lecture-Tutorials for Introductory Astronomy are then asked to craft a response to the question of which student, if either, do you agree with.  In this way, students are given the opportunity to safely judge the accuracy of distant hypothetical students’ thinking rather than directly confront their own personal thinking.  In this sense, the task is less risky than revealing their own personal views and are apt to take more risks at exposing their own potentially incorrect thinking, thus positioning themselves to learn complex astronomy ideas themselves.

More than 100,000 astronomy students have used Lecture-Tutorials with varying degrees of success.  By and large, our experience is that most people who have used them, continue to use them course after course.  At the same time, talented teachers are creating Lecture-Tutorials to cover concepts across the domain of astronomy, and even moving into other disciplines.  There is even a 15-min. YouTube video on how to make your own available at http://www.youtube.com/user/CAPERTeamTube.

Many of these new and community created Lecture-Tutorials are archived and freely available at the Astronomy Faculty Lounge which can be accessed through the FACULTY LOUNGE portal at the CAPER Center for Astronomy & Physics Education Research website at www.caperteam.com (Slater & Slater, 2013).

PERHAPS SOME USEFUL REFERENCES

Brogt, E. (2007). A theoretical background on a successful implementation of lecture-tutorials. Astronomy Education Review, 6, 50.

Bybee, R. W. (Ed.). (2002). Learning science and the science of learning: Science educators’ essay collection. National Science Teachers Association, Publisher.

Karplus, R., & Butts, D. P. (1977). Science teaching and the development of reasoning. Journal of Research in Science Teaching, 14(2), 169-175.

Lombardi, D., & Sinatra, G. M. (2010). College students’ perceptions about the plausibility of human-induced climate change. Research in Science Education, 1-17.

McDermott, L. C. (2001). Oersted Medal Lecture 2001:“Physics education research—the key to student learning”. American Journal of Physics, 69, 1127.

Prather, E.E., Slater, T.F., Adams, J.P. Bailey, J.M., Jones, L.V., & Dostal, J.A. (2004). Research on a Lecture-Tutorial Approach to Teaching Introductory Astronomy for Nonscience Majors.  Astronomy Education Review, 3(2), 122-136.

Prather, E.E., Slater, T.F., Adams, J.P. & Brissenden, G. (2012). Lecture-Tutorials for Introductory Astronomy – 3rd Edition , Addison Wesley, ISBN:  0132392267

Prather, E. E., Slater, T. F., & Offerdahl, E. G. (2002). Hints of a fundamental misconception in cosmology. Astronomy Education Review, 1, 28.

Posner, G. J., Strike, K. A., Hewson, P. W., & Gertzog, W. A. (1982). Accommodation of a scientific conception: Toward a theory of conceptual change. Science education, 66(2), 211-227.

Slater, T.F. (2010). Enhancing Learning Through Scientific Mini-Debates. The Physics Teacher, 48(6), 425-426.

Slater, T.F. & Slater, S.J. (2013).  Next Generation Astronomy Faculty Lounge.  Online teaching resource library and community forum hosted by CAPER Center for Astronomy & Physics Education Research, URL: http://www.caperteam.com

Slater, T.F. & Zeilik, M. (2003). Insights Into the Universe:  Effective Ways to Teach Astronomy, American Association of Physics Teachers Press: College Park, MD (160 pages).  ISBN:  1-931024-04-9

Strike, K. A., & Posner, G. J. (1992). A revisionist theory of conceptual change. Philosophy of science, cognitive psychology, and educational theory and practice, 147-176.