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Excerpts from


Peer Instruction for Astronomy





Paul J. Green
To be published by
Prentice Hall 2002

Visit the Web site and ConcepTest Library at

http://hea-www.harvard.edu/~pgreen/educ/PIA.html







CONTENTS

FOREWORD by Eric Mazur
PREFACE
Chapter 1: INTRODUCTION
Chapter 2: PEER INSTRUCTION FOR ASTRONOMY
ACTIVE LEARNING: ENGAGING THE EGO AND THE MIND
COOPERATION AND COMMUNICATION
CRITICAL THINKING
BENEFITING FROM DIVERSITY, AND ENHANCING IT
KEY COMPONENTS OF COOPERATIVE LEARNING
UNEARTHING PRIOR KNOWLEDGE
OVERCOMING POTENTIAL BARRIERS TO PEER INSTRUCTION
Chapter 3: RECIPES FOR THE CLASSROOM
DAY ONE
A BRIEF RECIPE
HOW TO GAUGE STUDENT UNDERSTANDING IN REAL-TIME
HOW TO SELECT GROUPS
HOW TO BUILD STUDENT COLLABORATIVE SKILLS
HOW TO FACILITATE DISCUSSIONS
Chapter 4: CONCEPTESTS
ACCESSING CONCEPTESTS
CREATING CONCEPTESTS
USING CONCEPTESTS
CONCEPTEST FEEDBACK
Feedback from Students
Feedback from Instructors
Chapter 5: A LIBRARY OF CONCEPTESTS
THE NIGHT SKY
General
The Celestial Sphere
Seasons
Time
Eclipses
MEASURES & METHODS
Measures & Units
Distance
Magnitudes
Astronomical methods
TELESCOPES
HISTORY
GENERAL MOTION/FORCES
Orbital Motion
Forces & Acceleration
Gravity
SCALES OF SIZE, DISTANCE, MASS & POWER
THE ELEMENTS
RADIATION & THE ELECTROMAGNETIC SPECTRUM
General Properties of Light
Continuous Radiation, Emission & Absorption
Doppler Effect
Spectral Lines and Energy Levels
THE EARTH
EARTH & MOON
THE MOON
THE PLANETS
ASTEROID, METEORS & COMETS
THE SUN
BASIC STELLAR PROPERTIES
STAR FORMATION
ENERGY GENERATION IN STARS & STELLAR EVOLUTION
Energy generation in stars
Stellar evolution
Black Holes
BINARY STAR SYSTEMS
General Concepts of Binary Stars
Binary Classifications & Uses
Binary System Light curves
STELLAR POPULATIONS
Constellations
Star Clusters
OUR GALAXY
NORMAL GALAXIES
ACTIVE GALAXIES & QUASARS
COSMOLOGY
The Hubble Expansion
Cosmology
Large Scale Structure & the Cosmic Background Radiation
DARK MATTER & LENSING
ORIGIN & EVOLUTION OF LIFE
Chapter 6: ASSESSMENT
EARLY DIAGNOSTIC ASSESSMENT
THE ASTRONOMY DIAGNOSTIC TEST
INTERACTIVE CLASS ASSESSMENT
READING ASSIGNMENTS & READING QUIZZES
EXAMS
OVERALL CLASS GRADING
EVALUATING YOUR IMPLEMENTATION
Group Instructional Feedback
Course End Evaluations
Instructor Feedback
CROSS-INSTITUTIONAL EVALUATION
Chapter 7: EPILOG
Chapter 8: READINGS & RESOURCES
READINGS
WEB RESOURCES
REFERENCES
APPENDIX 1: CDROM INSTRUCTIONS
APPENDIX 2: THE ASTRONOMY DIAGNOSTIC TEST
INDEX
Chapter 1: INTRODUCTION

(excerpts)


As any teacher knows, the real test of learning is to be able to explain
what you've learned to others. Regardless of the subject matter, when
students are actively involved, they learn more and retain it longer than
when they try to absorb knowledge passively. Small group learning
techniques are now in use in science classes all over the country.
Students are becoming accustomed to this method in high schools, and will
not be surprised to see it in introductory college astronomy. Various forms
have been tested and evaluated, and are even now being sculpted by
experience in the class and laboratory. Students who work collaboratively
report more satisfaction with their classes (Beckman, 1990; Cooper et al.
1990; Johnson, Johnson, and Smith, 1991a). This form of learning has a
variety of names and implementations falling under the classification of
collaborative learning (CL), including cooperative learning, collective
learning, peer teaching, peer learning, Peer Instruction, team learning,
study circles, study groups, work groups, etc.


Group work can take the form of informal learning groups, formal learning
groups, or study teams. The latter two usually are formed for projects
that span many classroom or laboratory sessions, with the aim of completing
a project. Peer Instruction for Astronomy focuses on what instructors can
do in class to boost student learning and satisfaction, and so the emphasis
here is on informal learning groups. These are temporary clusters of
students, formed as needed, often within a single class session.


These informal groups help gauge students' understanding of the material,
allow students to apply what they are learning, and provide a change of
pace. Peer Instruction (sometimes called peer teaching) is a form of
collaborative learning. Peer Instruction has been developed and
implemented for introductory Physics by Eric Mazur at Harvard University.
The improvements in student performance have been widely publicized in
Sheila Tobias' book Revitalizing Undergraduate Science (Research
Corporation, 1992). By encouraging student participation and interaction
during lecture, Peer Instruction encourages students to critically think
through the arguments being developed, and to discuss and defend their
ideas and insights with their neighbors. At any time and in a class of any
size, you can implement Peer Instruction. For instance, you may simply ask
students to turn to a neighbor for 2 minutes to solve a puzzle or question
you've just posed during a lecture.

The goal of this book is to facilitate the implementation of Peer
Instruction in introductory astronomy classes by providing ideas,
guidelines, and a wealth of examples ready for your use in the classroom.
First, I'll outline active learning techniques like Peer Instruction, and
the wealth of usage and research behind them. When you first undertake to
incorporate Peer Instruction, you will not be alone! I will also provide
detailed classroom recipes for the implementation of Peer Instruction, with
specific examples. A broad library of ConcepTests forms the core of the
book. ConcepTests are short, conceptual multiple-choice questions for use
during class, that serve to gauge comprehension of scientific principles in
real-time, to challenge misconceptions, and to foster student engagement
through Peer Instruction. All along the way, I provide quick summaries of
how to implement Peer Instruction in the classroom for the harried
instructor. In addition, I will encourage you to participate in a broad
range of assessments. I describe options for assessing your students, and
for evaluating your own implementations of Peer Instruction for Astronomy
using input from students or colleagues. I also invite you to join a broad-
based collaboration of instructors working to enhance Peer Instruction by
building and improving the library of ConcepTests, and by assessing and
improving Peer Instruction itself using data from the field - the reported
experiences of you and other astronomy instructors.



Chapter 3: RECIPES FOR THE CLASSROOM


Don't panic. There is no need to throw away your lecture notes and
radically restructure your class for the next semester. Implementation of
Peer Instruction can happen gingerly if you prefer. Of the many college
and university classes using cooperative learning techniques, most employ
them between 15 and 40% of the available class time (Cooper 1990, ref. in
Millis & Cottell p14). These techniques supplement, but need not replace,
direct instruction and lectures



1 A BRIEF RECIPE


Briefly, lectures are broken into sections covering key points. Start with
a more-or-less standard format mini-lecture on one of the fundamental
concepts to be covered. This mini-lecture might last about 10 minutes, and
is then followed by a ConcepTest, a short multiple-choice question that
tests the students' understanding. After one minute, you may ask the
students to record or display their individual answers. Recording the
initial answers affords the opportunity to track the improvements in
understanding that Peer Instruction later builds. You may then ask
students to turn to their neighbors to try and convince them of their
individual answers. This invariably leads to animated discussions. After
another minute or so, the students are asked to reconsider their answer and
record it again. You then take quick poll to decide whether to move on to
the next concept, or to continue exposition on the same material. A
variety of options are available to suit your taste; some are sketched
below. The process, lecture/test/discuss/retest, may repeat several times
until the end of the class. Depending on the material, you may thus expect
to cover 3-4 key points during a typical one hour lecture period. When you
implement Peer Instruction in your classroom, a good plan might be to break
your lecture outlines into 3-4 subsections.





As an example, a lecture on quasars can be broken up as follows:



1. How nearby `active' galaxies differ from normal galaxies

2. Evidence for supermassive black holes

3. Quasar distances and luminosities

4. The epoch of quasar formation


Before class, you can choose (or compose) a couple of ConcepTests for each
key point you plan to cover. Following your mini-lecture on one such
point, the briefest possible use of a ConcepTest might be as follows -
simply as a real-time gauge of class comprehension.


2 ConcepTests for Feedback Only - High Comprehension

1. Mini-lecture
2. Quick-read tally via ConcepTest
Yields >90% correct answers
3. Identify and explain the correct answer
4. Move on

After every ConcepTest, you should allow a moment for an explanation, even
when the vast majority of students chose the correct answer the first time,
without recourse to peer discussions. First, an explanation should be
available to those students who did answer incorrectly. Second, some
students will glean the correct answer without true understanding, either
from wording, context or from watching others.

After a ConcepTest, you may instead discover that comprehension is so low
that you feel the students should not try to convince each other of the
correct answer since so few of them know it.


3 ConcepTests for Feedback Only - Low Comprehension

1. Mini-lecture
2. Quick-read tally via ConcepTest
Yields <20% correct answers
3. Continue mini-lecture, allow for greater detail, review and questions
4. Re-tally with a new ConcepTest to gauge comprehension

The figures of 90% and 20% are of course simply suggestions. Use your own
judgment. If the comprehension is intermediate, as is most often the case
for well-chosen ConcepTests, then Peer Instruction comes fully into play.
Here I provide some time estimates as a guide.

2 ConcepTests with Peer Instruction

1. Mini-lecture (10 minutes)
2. Pose ConcepTest (1 minute)
3. Quick-read tally (1 minute)
Yields 30-80% correct answers
4. Students break into peer groups for discussion (2 minutes)
5. Re-tally after discussion (1 minute)
6. Iterate or move on

If students have already had their first peer group discussion, and a tally
shows that a significant but not overwhelming fraction (say half) of the
groups found the right answer, then you can ask each group to combine with
the nearest group that has chosen a different answer. For a concept this
knotty, I suggest allowing about 4 more minutes of discussion for the new
large groups to arrive at a single answer.

For Peer Instruction, the largest and most crucial investment of
instructors' time is in choosing good ConcepTests that fall in the middle
group, allowing students to teach each other most effectively. This
generates the greatest student engagement, but also relieves you from
having to cram material into a full-time lecture, since you now emphasize
key concepts over rote learning. I cover hints for constructing good
ConcepTests later on, and a primary goal of this book is to provide many of
them, so that the skids are greased for your foray into Peer Instruction.

Now you can see that in the most common situation, covering a key topic
should take just about 15 minutes of class time, even allowing for the real-
time feedback and the student interaction and discussion that Peer
Instruction provides. While the back-and-forth with students may seem to
throw a wrench into the clockwork of a traditional lesson plan, your
adaptation will be easier than you might think. Wander around and listen to
the discussions and debates going on. While the students deliberate, you
will have some time to think, and an opportunity to evaluate where any
confusion might lie and how to address it.



Chapter 4: CONCEPTESTS

(excerpts)

Short, conceptual, multiple-choice questions can be used for two purposes
simultaneously - feedback and learning. Feedback gives you the ability to
quickly gauge student comprehension during class, allowing real-time
adaptation of the lecture. Learning is facilitated by challenging students
to reorder their preconceptions and confront their misconceptions by
discussing conceptual puzzles with peers in a collaborative atmosphere.


1 Accessing ConcepTests


One of the most labor-intensive parts of using Peer Instruction is the
creation of a large collection of appropriate multiple choice `puzzlers' of
this type. A significant number would be needed simply to cover all the
many major topics spanned by most beginning college astronomy courses.
However, since class levels vary dramatically both within and between
institutions, an even larger collection is advisable. The sample of
ConcepTests provided in this chapter is meant to ease an instructor's entry
into Peer Instruction for Astronomy. This collection contains
contributions from instructors across the country, and should be considered
a truly collaborative, ongoing community effort of astronomy educators who
are interested in progress and innovation in the classroom. The
ConcepTests Library remains accessible on the web at
http://hea-www.harvard.edu/~pgreen/PIA.html

Astronomy instructors can both access and contribute to this library.
Furthermore, as discussed later, feedback from instructors on the content
and scoring of individual ConcepTests will be used to continually adapt and
refine the Library in the future, making it a dynamic, accessible tool
suitable for direct use in the classroom, but also as a potential database
for research on and assessment of the technique of Peer Instruction and its
results.



Chapter 5: A LIBRARY OF CONCEPTESTS

(excerpts)

The Night Sky

The reason stars twinkle is because of motion
a) on their surface.
b) of the Earth.
c) of the Solar System.
$d) of gas in Earth's atmosphere.
e) relative to the observer.

Which of the following stellar properties can you estimate simply by
looking at a star on a clear night?
a) Distance.
b) Brightness.
c) Surface temperature.
d) Both a and b.
$e) Both b and c.


Seasons

What causes winter to be cooler than summer?
a) The Earth is closer to the Sun in summer than in winter.
b) The daylight period is longer in summer.
c) The Sun gets higher in the sky in summer.
$d) both B and C.
e) all of the above.

Imagine a planet whose rotation axis is perpendicular to its orbital
plane. How would you describe its seasons?
a) shorter than those on Earth.
b) longer than those on Earth.
$c) constant.
d) the same as those on Earth.


Orbital Motion

Kepler's 3d law (that the period squared is proportional to the semi-major
axis cubed) does NOT apply to the motion of
a) a satellite around the Earth.
b) a comet around the Sun.
c) one star about another in a binary star system.
d) one galaxy about another.
$e) All of the above apply.

A description for the relationship between the period of revolution P and
the distance from the center R of a point on a record on a turntable would
be
a) P^2 is proportional to R^3.
b) P^2 is proportional to R.
c) P is proportional to R.
$d) P does not depend on R.

Forces & Acceleration

Which situation(s) does NOT describe an acceleration:.
$a) a car traveling with constant speed on a straight road.
b) a car traveling with constant speed around a bend.
c) a planet traveling in its orbit around the Sun.
d) a car decreasing speed on a straight road.
e) an electron traveling around a nucleus.

The escape velocity from the Moon is less than that from the Earth because
of the Moon's
a) lower density.
$b) smaller mass.
c) smaller radius.
d) higher temperature.
e) distance from the Earth.


Scales

The establishment of a reliable cosmic distance scale is a "bootstrap
process" because
a) distance steps are all calibrated independently.
$b) each distance step calibrates the next step.
c) scientists build from past work.
d) the Hubble Constant calibrates all the steps.

The cosmological principle enables astronomers to generalize from what
they observe to the properties of the universe as a whole. The principle
states that any and all observers, everywhere in space, should see, on
average, the same picture of the universe as us on scales comparable to
a) the Solar System.
b) the galaxy.
$c) superclusters of galaxies.
d) atoms and subatomic particles.

The distance between the Sun and its nearest star is smaller than the
distance from the Milky Way Galaxy to the next nearest large galaxy
Andromeda by a factor of about
a) a hundred.
b) a thousand.
$c) a million.
d) a billion.

Continuous Radiation, Emission and Absorption

A star with a continuous spectrum shines through a cool interstellar cloud
composed primarily of hydrogen. The cloud is falling inward toward the
star (and away from Earth). Which best describes the spectrum seen by an
Earthbound observer?
a) blueshifted hydrogen emission lines
b) blueshifted hydrogen absorption lines
c) redshifted hydrogen emission lines
$d) redshifted hydrogen absorption lines
e) a redshifted hydrogen continuum

The Sun

Compared to the Sun, most other stars in the Milky Way Galaxy are
a) as small relative to the Sun as they appear in the sky.
$b) smaller.
c) about the same size.
d) much larger.

The photosphere (the visible surface) of the Sun is like
a) the surface of the Earth; you could stand on it, if you could
survive the heat.
b) the surface of the ocean; you couldn't stand on it, but you would
clearly be able to detect differences above and below it.
$c) an apparent surface; you would notice very little change as you go
through it, as when you fly through a cloud.
d) the surface of a trampoline; you could land on it, but the intense
pressure would push you away again.


Energy Generation in Stars

Why does fusion of hydrogen release energy?
a) Fusion breaks the electromagnetic bonds between hydrogen atoms,
releasing energetic photons.
$b) The mass of a helium nucleus is smaller than the mass of four
protons.
c) The mass of a helium nucleus is larger than the mass of four
protons.
d) The velocity of four protons is larger than the velocity of a helium
nucleus.
e) None of the above are true.

Why would two protons combine to form an atom of deuterium (heavy
hydrogen) in the core of a star like the Sun?
a) The electromagnetic force strongly attracts the protons.
b) The gravitational force strongly attracts the protons.
$c) The velocity of protons in the core of the Sun is very large.
d) Protons never combine to form deuterium in the core of the Sun.
e) Both a and c.


Stellar Evolution

If two stars burning hydrogen in their cores (are on the main sequence),
and one is more luminous than the other, we can be sure that the
a) more luminous star will have the longer lifetime.
b) fainter star is the more massive.
$c) more luminous star is the more massive.
d) more luminous star will have the redder color.

You are an immortal alien being, hiding in the photo archive room of a
library on Earth. You can best learn about the life cycles of people by
bringing home the drawer filled with photographs of
a) individuals.
$b) crowds on the street.
c) people lined up at the voting both.
d) doctors.


The Hubble Expansion

Your job is to compile a representative catalog of galaxies. Assuming our
region of the universe is typical, the best criterion to use to decide
whether to include galaxies in the catalog is to include all galaxies on
the sky with
a) magnitudes brighter than some chosen limit.
b) apparent diameters larger than some chosen limit.
$c) recession velocities less than some chosen limit.
d) surface densities of stars larger than some chosen limit.

Suppose the universe were not expanding, but was in some kind of steady
state. How should galaxy recession velocities correlate with distance?
They should
a) be directly proportional to distance.
b) reverse the trend we see today and correlate inversely with
distance.
c) show a scatter plot with most recession velocities positive.
$d) show a scatter plot with equal numbers of positive and negative
recession velocities.

Suppose the Hubble Constant were measured and found to be twice as large as
it is now believed to be. The implied maximum age of the universe in a Big
Bang model would be
$a) halved.
b) the same.
c) doubled.
d) squared.


Cosmology

Which of the following observations about the nature of the universe can be
made with only a small telescope?
a) The universe is expanding.
b) Most of the matter in the universe does not emit light.
$c) Luminous matter in the universe occurs in clumps rather than being
evenly distributed.
d) There is background radiation in all directions that came from the
Big Bang.

The cosmological principle enables astronomers to generalize from what
they observe in the nearby universe to the properties of the universe as a
whole. The principle means that no matter where you are in space, you
should see that
a) galaxies are all moving away from the same point.
b) the universe does not change with time.
$c) space looks approximately the same in all directions.
d) every region of space is unique.

Olber's Paradox asks why the night sky is dark, when every line of sight
must eventually fall on a star. Which of the following reasons would best
explain the darkness at night? It is because the universe is
a) infinite and mostly empty.
b) clumpy, so not every sightline intercepts a star.
c) expanding, so distant stars are redshifted.
$d) young, so there are only stars to a finite distance.


READING ASSIGNMENTS & READING QUIZZES


Peer Instruction relies heavily on students having read the relevant
assigned material before class. Only then can they have the knowledge and
insight necessary for fruitful interactions with the instructor (via
ConcepTests) and with other students (in their discussion groups).

Below I include an example of the web form that I use for reading quizzes.
The web form is at a standard web address of which I remind students in
class. The quizzes are due before the next class begins, as indicated on
the web form. When students fill out the form and submit it, I receive a
standard format response that is easy to grade and tally. Below the
responses, space is offered for a quick assessment of student confidence,
or for comments about the quiz or readings.




CHAPTER 7: EPILOG

Try Peer Instruction in your college introductory astronomy class. It's
not hard to implement, and yields rapid rewards for both you and your
students. While Peer Instruction is scalable to your level of interest and
commitment, you will benefit by putting much more than a toe in the water.
Experience shows that a full implementation, meaning two or three
ConcepTests and discussions per lecture hour, accomplishes a lot. Peer
Instruction for Astronomy, thoughtfully administered will almost surely

1. raise class attendance and lower course attrition.
2. boost and hold the interest of your students.
3. heighten your awareness of students' comprehension.
4. highlight common misconceptions to be addressed directly in
lecture.
5. increase student understanding of key physical concepts.
6. improve student retention.
7. develop students' ability to communicate scientific ideas.
8. enhance students' collaborative skills.
9. raise student satisfaction with your course and appreciation of
your teaching.

Now, why should you buy all that? While there is a huge body of research
documenting the effectiveness of cooperative learning techniques like Peer
Instruction, the effectiveness of the specific techniques discussed here,
and their particular application to astronomy have only begun to be
studied. Are all the above points true? In what circumstances? How can
you trouble-shoot your implementation of Peer Instruction for Astronomy?
It is crucial that the experience of teachers like yourself be shared in
the community of astronomy instructors and educators. Peer Instruction for
Astronomy should be researched and documented in detail. Don't just go it
alone. Check the web sites, readings, and references below so we can all
learn and benefit from each other. Share the wealth!

Chapter 8: READINGS & RESOURCES
(excerpts)


http://aer.noao.edu
The Astronomy Education Review, hosted by the National Optical Astronomy
Observatories, has articles on a broad range astronomy and space science
education topics, ideas for innovative teaching and outreach, funding
opportunities, meeting announcements etc.

http://www.astrosociety.org/education/resources/resources.html
The Astronomical Society of the Pacific's Education Resource page, authored
in large part by Andy Fraknoi, lists and links astronomy education projects
and resources in the U.S., and provides publications, some free.

http://solar.physics.montana.edu/aae/adt/ or
http://www.aacc.cc.md.us/scibrhufnagel/
The Astronomy Diagnostic Test is provided in the Appendix of this book, but
updates, statistics of usage, and a Spanish language version are provided
at this web site.

http://shiraz.as.arizona.edu/
The Conceptual Astronomy and Physics Education Research (CAPER) team's
mission, focussing on collaborative learning strategies, is to develop and
disseminate effective instructional interventions and authentic assessment
strategies based on research in student understanding. The team conducts
research and public outreach activities in the areas of physics, astronomy,
and earth/space science.

http://hea-www.harvard.edu/~pgreen/PIA.html
At this Peer Instruction for Astronomy web site, the ConcepTests Library
from Chapter 5 remains accessible on the web where Astronomy instructors
can both access and contribute. Feedback from instructors on the content
and scoring of individual ConcepTests will be used to continually adapt and
refine the Library in the future, making it a dynamic, accessible tool
suitable for direct use in the classroom, but also as a potential database
for research on and assessment of the technique of Peer Instruction and its
results.

http://mazur-www.harvard.edu/education/pi.html
Peer Instruction for physics by Eric Mazur's group at Harvard explores
collaborative learning in large lectures. The related site
http://galileo.harvard.edu/home.html from the Galileo project includes a
growing, searchable database of ConcepTests for Physics and other sciences.
Mazur's method is described in Peer Instruction: A User's Manual (see
Readings), where Physics ConcepTests are provided. The book also includes
two nationally recognized evaluation tools, the Force Concept Inventory and
the Mechanics Baseline Test, usable as pre-tests and post-tests to evaluate
both teaching effectiveness and student learning. Reading quizzes,
conceptual exam questions, and ConcepTests intended for a one year
introductory college physics course are included.