Constructing a sustainable foundation for thinking and learning about energy in the 21 century

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Constructing a sustainable foundation for thinking and learning about energy
in the 21
st
century

Lane Seeley

& Stamatis Vokos
, Seattle Pacific University

Jim Minstrell, Facet Innovations



Addressing the energy challenges of today and tomorrow will require energy experts in
fields from
municipal government

to public health. These experts will draw from their diverse,
sophisticated and nuanced understandings of energy and society which go far beyond static lists
of energy facts or forms. They will need to think and communicate using energy concepts that
ar
e flexible, relevant, and negotiated.

Historically energy instruction has been
compartmentalized and rigid. Students often associate the energy ideas they learn in school as a
regimented program of taxonomy and bookkeeping. They understand their task a
s correctly
identifying forms and tabulating transfers and transformations. Students also learn a scientific
concept of energy that is conserved; yet live in a world in which people are constantly ‘using up’
energy. Students need to recognize energy as a

universally applicable model for making sense of
processes and resources

in the physical world.



The Energy Project at Seattle Pacific University



The Energy Project is a five
-
year NSF
-
funded project
with
an overarching goal

of

increasing
learner engagement with energy in K
-
12 classrooms.

We work directly with
elementary and secondary teachers’
to help them build their personal understanding and

formative assessment practices in the context of energy. Our goals for energy learning include
:



Flexible a
ppl
ication

of
the c
onservation

principle

and tracking

of energy in
‘real
-
world’
processes



Construct
ion

of a personally owned
energy model which can be flexibly applied to novel
scenarios.



Recogni
tion

of
the affordances and limitations of

various

energy representations
.



Application of energy models and representation
al strategies

to socio
-
politically relevant
energy questions.

Our progress toward some of these goals is reported elsewhere (E. W. Close, Scherr, Close, &

McKagan, 2011; H. G. Close, DeWater, Close, Scherr, & McKagan, 2010; H. G. Close &
Scherr, 2011; Harrer, Scherr, Wittmann, Close, & Frank, 2011; McKagan, Scherr, Close, &
Close, 2011; Scherr, Close, Close, & Vokos, 2012; Scherr, Close, McKagan, & Vokos, 2
012).
In
this paper we will describe how we have
worked toward the
preceding

goals in

workshops for K
-
12

teacher
s


by:



Providing representational strategies which recruit learner ideas,
mandate energy
tracking,
encourage sense making and promote scientific
questioning.



Explicitly and implicitly reinforcing the idea that scientific language, representations and
classification strategies are inherently subjective and
negotiated
.



Scaffolding productive learner engagement with specific scenarios that foreground
complex and subtle aspects of the energy concept.


We will also share some preliminary evidence of significant changes in learner engagement with
energy concepts.
We will conclude by discussing the critical, and in our minds unsolved
challenge of developi
ng a pedagogically accessible model for energy use,
usefulness

and
degradation that makes sense to learners and is widely applicable.


I. Providing representational strategies which recruit learner ideas,
mandate energy
tracking,
encourage sense making and promote scientific questioning


Energy is an inherently abstract concept. We don’t see or touch or measure energy
directly
and the ev
idence for energy comes in a wide range of forms. Therefore, it is essential
that learners construct meaningful representations of energy. Energy representations should be
flexible enough that learners feel empowered to apply them to a wide range of scen
arios and
energy ideas. They must also be rigorous enough to problematize and refine learner thinking
about energy. The Energy
P
roject
has promoted two dynamic energy representations, Energy
Theater and Energy
Cubes
,

which

we find helpful for supporting constructive and creative
thinking about energy. We have also
encouraged

learners to draw
E
nergy
T
racking
D
iagrams
which capture dynamic energy processes in a static diagram.


Energy Theater

Energy Theater is an activity
introduced by Scherr
, Close, Close and Vokos
(2012) that
uses the body to represent a “chunk” of energy. Groups of 8
-
12 participants “become” chunks of
energy and must “act out” the transfer(s) and/or transformation(s) of energy associated with
sp
ecific scenarios.
Energy Theater
encourages learners to express their thinking about energy
with their bodies and provides learners with a personal and bodily experience of energy
conservatio
n. The rules of
Energy Theater are:



Each person is a unit of

energy



Regions on the floor correspond to objects
involved
in the
selected

scenario



Each person indicate
s
h
is
/her form of energy in some way (usually with a hand sign).



People move from one region to another as energy is transferred, and change sign as
the
energy changes form.



The number of people in a region or making a particular hand sign corresponds to the
quantity of energy in a physical object or of a particular form, respectively.


Figure 1 shows a group of secondary science teachers who are u
sing
E
nergy
T
heater to represent
the ‘energy story’ associated
with a hand pushing a box across a floor at constant speed. The
teachers on the left are representing chemical

and motion/kinetic

energy in the person/hand. The
teachers at the left are
representing motion and thermal energy in the box
, Other

teachers are
leaving the box as thermal
and sound
energy into the floor and air.



Figure 1
-

“Energy Theater” representation of
a hand pushing a box
across a floor at constant
speed. (
Used
with permission from Scherr
, Close, Close & Vokos
(2012).
)


Energy Theater is pedagogically useful because it:



Promotes universal participation


Because
everyone

is part of the representation,
each learner has to participate in the process of negotiating the energy transfers and
transformations that are involved in a chosen energy scenario.



Provides opportunities for formative assessment


Because learners represe
nt
energy processes in a public way, teachers and other learners have an opportunity to observe
and respond to the ideas of others.



Encourages negotiation and consensus building


Energy Theater provides a
supportive context for negotiating energy ideas.
Learners will often spontaneously form a
discussion circle during the planning stage and must reach (at least tentative) consensus in
order to enact their representation.



Encourages attention to energy conservation


Many students in secondary
science c
ourses are familiar with energy conservation. A central conceptual challenge in
learning about energy is figuring out how energy is conserved in a wide array of dynamic
physical processes. This involves answering questions like: Where does the energy st
art?
Where does it go after that? What form does the energy take along the way? Energy Theater
mandates energy conservation because learners


who represent units of energy


cannot
spontaneously appear o
r

disappear. The learners must negotiate where
to begin, where and
when to move, and what form to exhibit along the way.



Balances creativity with representational rigor


The rules of Energy Theater
challenge learners to devise a sequence of energy transfers and transformations that satisfy
conservatio
n of energy and correspond to a given physical scenario. Simultaneously,
Figure 2. “Energy Cubes” representation of
a hand lifting a box vertically. (
Used

with
permission from Scherr
, Close, Close

&

Vokos
(2012).
)


learners must make a number of representational choices based on what they think is
important to show.


In an upcoming paper we
describe
teachers

using Energy Theater to explore the energy processes
associated with an incandescent light

bulb that is
providing constant illumination. In this case,

Energy Theater
supports learner efforts to
disambiguate

matter an
d energy
. They are challenged
to
differentiate between

electrons which
flow around the circuit

and the energy that those
electrons carry from the
wall outlet to the filament.
We also describe how
Energy Theater
provides a shared representational space for
learners

to

theorize mechanisms of energy transfer.

In order to negotiate a sequence of energy steps for an incandescent light

bulb, the teachers are
compelled to decide whether the
electrica
l

energy is converted directly into light energy or if the
fi
lament glows because it is hot.



Energy Cubes

Energy Cubes is an activity in which
learners use small cubes to represent “chunks” of
energy. Designated regions on a whiteboard
represent objects of interest. Groups of 3
-
5 learners
move and flip these cubes on the
whiteboard
to
dynamically represent the transfer(s) and/or
transformation(s) of energy associated with specific
scenarios
.

For example
in figure 2 which depicts
an

energy cubes representation of a person lifting a
box at constant
speed a learner might

represent t
he
;



e
nergy

conversion

associated with
the
physiological

effort
of raising the hand by
flip
ping

a
n energy

cube in the hand from
displaying a
‘C’ for chemical energy to
showing a ‘K’

for kinetic energy



mechanical transfer of energy from the hand to the box by moving an energy cube
showing
‘K’ from the region

depicting the hand to the region depicting the box



increase in gravitational energy of the box by flipping an energy cube
in the box from
showing
‘K

to showing ‘G’ for gravitational energy



mechanical transfer of energy from the box to the air
by moving an energy cube showing
‘K’ from the region depicting the
box

to the region depicting the
air



dissipation of collective air motion by
flipping an energy cube in the
air

from showing
‘K’ to showing ‘
T
’ for
thermal

energy

Energy Cubes provide
s

some of the same pedagogical affordances as Energy Theater while
allowing learners to work in smaller groups. Energy Cubes do not necessitate universal
participation since participants can choose to let others flip and move the cubes.

L
earners can be

challenged to coordinate thei
r motions in order to show
, for example, the constant speed
associated with the box lifting scenario. The
y

would need to recognize that con
s
tant speed
implies contant amounts of kinetic energy in the hand and box. Then, they

would be challenged
to choreograph th
eir

‘moves’ so that the number of K’s in both of these objects does not change.

Additional energy scenarios for which we have used Energy Theater and Energy Cubes to
engage and problematize learner thinking about energy are described below.


Energy Tracking Diagrams

Energy Tracking Diagrams are learner
-
invented representations of energy processes.
Learner
s work in groups to draw a static representation (on a whiteboard
; e.g. Figure 3
) of the
dynamic representation they constructed using Energy Theater or Energy Cubes
. In constructing
these diagrams learners are challenged to show all of the information that would be needed to
recreate the dynamic representation in Energy Theater or Energy Cubes. The results is a diverse
array of strategies for representing steps that

have a complex distribution in space
and

time
as
described by Scherr, Close, Seeley and McKagan (2012).




Figure 3. Learner
-
invented representations that track energy transfers and transformations in (a)
a ring launched across the floor by a bent
-
ba
ck meter stick; (b) an

incandescent lightbulb burning
steadily
;
(c)

incandescent and compact fluorescent light bulbs; (d) a pumped balloon; (e) a runner
eating pasta; (f) a pullback car; (g) a person pushing a chair. (Taken with permission from
Scherr
, Close, Close & Vokos
(2012)
.)


Scherr
, Close, Close & Vokos
(2012)
claim that


t
he variety in the diagrams’ surface
features is a testament to the learners’ creativity and originality in producing the diagrams. The
diagrams are entirely original in the sense that to our knowledge, no similar diagrams appear in
text
books or in prior energy instruction that the learners may have had. We consider these
diagrams to be evidence that our participants have, and are making good use of, the creativity
that will be required of them to translate their energy learning into acti
vities for their own
classrooms. Research suggests that activities in which learners invent representations may have
hidden efficiencies, leading to strong gains in procedural skills, insight into formulas, abilities to
evaluate data from an argument, and
transfer of learning to other contexts

(
Podolefsky and
Finkekstein (2007),
Scwartz and Martin (2004))

Underlying the apparent variety of the
diagrams, however, are deeper regularities. These regularities show that the features that
learners consider
important to represent are the very features that indicate a substance model
for energy and enable tracking of energy transfers and transformations: i.e., energy is
conserved, emplaced, located in objects, transfers among objects, accumulates in objects, a
nd
changes form. Learners who encode the deep structure of problems in self
-
generated
representations are more likely to transfer their understanding of those problems to new
contexts
. (Swartz (2009))



II)
Explicitly and implicitly reinforcing the idea th
at scientific language and classification
strategies are inherently subjective and
negotiated


Energy is a technical science word
,

but it is also a word that learners hear and use many
times a day outside of science class. As a consequence
,

learners bring many productive ideas
about energy

and

they also use language about energy that they have acquired outside of the
science classroom. In
E
nergy
P
roject
workshops we have adapted a
n instructional approach to
the regimentat
ion of community discouse

which was introduced by Moses (2001) and the
Algebra Project.
Close, DeWater, Close, Scherr and McKagan

(2010) have previously described
the reasons for adopting the algrebra project approach,


“Our own (attempted) release

of control over topical coverage and instructional sequence (on
multiple instructional time scales) called for another framework to be introduced into instruction
in order to achieve some adequate level of discipline and accountability in classroom discou
rse.
Through the Algebra Project we found an alternative instructional method that seeks less to
direct the specific content of the learner
’s thinking and more to regiment the relationship
between that thinking and its expression and communication through

multiple representations.



The algebra project

instructional approach
foregrounds the distinction between
people talk

which
is intuitive and
feature talk

which has been negotiated

and regimented

within a scientific
community
. Feature talk
can take the form of language
,

and it can also take the form of
negotiated and regimented representational strategies. We challenge the participants to limit
their use of feature talk which has not yet been negotiat
ed by the community.
Initially it is t
he
workshop instructors who challenge participants to explain the meaning behind their scientific
language. Eventually a classroom culture is established in which

most participants are willing to
demand a negotiated understanding of new scientific termin
ology.
Below are several specific
examples where we think it is critical to negotiate and build shared understand
ing

from

energy
language.


Potential energy and the potential to have energy

Potential energy

is a phrase for which the regimented science meaning and popular
language meanings are disparate. Many learners associated the phrase potential energy with the
potential to have energy. For example, learners
may

claim that, “
the meter stick has potential
energy, (or potential elastic energy) because it is can be bent
.”
We have consistently found that
s
ome
learners will still use the phrase
potential elastic energy

even after instructors have
repeatedly referred to the en
ergy as
elastic energy

or
elastic potential energy
.
The phrase
potential elastic energy

is certainly more consistent with the idea of a potential to possess elastic
energy. For related reasons learners
may

say that
the bowling ball has potential energy or
potential kinetic energy because it
can be

lifted up or because it can be rolled, etc...)

In our
Energy Project workshops we
use ideas presented by Moses (2001) to foreground the difference
between an intu
itive

use of
potential

as people talk and a regimented use of that word as feature
talk.
Participants

discuss the difficulties which arise when some
members of

the learning
community are using the word in a scientifically regimented way and others are
understanding
the word intuitively. This provides a motivation for

negotiat
ing

language
that

is intuitive for
everyone.
For example,
elastic energy

is intuitively a type of energy, not a description of

an
objects elasticity or potential to have elastic en
ergy.


Heat energy, thermal energy and the kinetic energy of particles

While we prioritize the negotiation of
scientific
language we also recognize

that the
negotiation of scientific language
should

not occur in an isolated learning community. All
learners, and especially teachers,
should be sensitive to the regimented scientific language of the
broader scientific community

as
established through

scientific articles,
textbooks,
published
curricula,
state and national standards

One might conclude that the learners simply need to learn
and adopt the regimented language of the

broader

scientific community. Unfortunately the
regimented scientific language itself is often not consistent from one community to the next.
Kraus and Vokos (2011) did a scientific
nomenclature

study of energy concepts related to
temperature in widely used college textbooks, pre
-
college curricula and various
standards

documents
. They found a wide spectrum of terminology
used to describe

with the energy
contained by an object tha
t is dependent on its temperature, including heat, heat energy, thermal
energy, internal energy, average kinetic energy of the particles and translational part of the
kinetic energy of the molecules.
Kraus and Vokos
suggest

that
teacher
s


qualify

with the word
“energy” whatever terms they choose to use, as in “the object contains heat energy” or “there is
heat energy transferred from the warmer object to the cooler object.”
They further recommend
that teachers


begin first with

the phenomena and observations, for which you want to build a
scientific description. Next, as students begin to use new and different language to try to explain
their observations, ask learners to qualify exac
tly what they are
describing
.”
Energy Project
instructors
discuss and attempt to
model these recommendations in order

that teachers can ad
o
pt
them
for

their own teaching.


Classification of energy forms

Energy educators hold
many different
perspectives

on the preferred role
, or lack of a role,
for

forms within a pedagogically accessible energy model.
Falk
, Herrman and Schmid
(1983)
argued

that forms should be de
-
emphasized in energy instruction because
it is not always
possible to clearly de
lineate
energy

in this way. They argue to focus
instead
on energy carriers

which they de
fine as

the
‘substance
-
like
’ quantities which are transferred simultaneously with
energy (e
ntropy, momentum, charge, etc
…) The suggestion to de
-
emphasize energy forms has
been taken up by others (Brewe 2011) and has recently been incorporated in the
most recent

draft
of the Next Generation Science Standards in the U.S.
Since teachers will have to be responsive to
changing standards and curriculum we hope that they can be empowered with the idea that
forms
are subjective
.
For example,
the energy

associated with a solid

that
increases when temperature
increases may be described as thermal energy or internal energy. On the other hand the same
energy might be separated into
the
disordered kinetic energy
and disordered electric potential
energy associated with vibration of the m
olecular lattice.
I
n our Energy Project workshops we
aim toward an understanding of forms as ‘
categories of evidence for the presence (or change) of
energy


as described by McKagan et al. (2011).

We have seen participants in our workshops tak
e ownership of the subjective nature of
scientific classification. For example,
t
he
participants in one of our workshops suggested that

they use

‘phase energy’
to describe

the energy that a gas has more of than a liquid at the same
temperature.
One of the participants rationalized their scientific license to make up energy forms

as follows
,

“Isn’t it all arbitrary anyway?... I mean, you know, thermal energy
-

that’s an idea.
Like you could have called it pancake energy if you wanted to.”
This teacher appears to be
recognizing that energy forms are
subjective systems of categorization
and are flexible. The
ways in which we categorize forms will depend on what we care about

and the particular
problem we are trying to solve
.


III)

Scaffolding productive learner engagement with specific scenarios that foreground
complex and subtle aspects of the energy concept


Many learners are familiar with the mantra that “energy is never created or destroyed,”
but lack the inclination and/or tools to make sense of this principle in everyday scenarios. We
have chosen to use Energy Theater and Energy Cubes as primary strategie
s for representing
energy scenarios. In doing so, we have chosen representational strategies which mandate energy
conservation. As long as people, or cubes, don’t come into being or cease to exist, energy is
conserved. Therefore, learners are not challe
nged to decide
if

energy is conserved but rather
how

energy is conserved. This challenge typically leads to two fundamental questions, where
does the energy come from and where does the energy go? We specifically choose to present
physical scenarios for
which these questions problematize learner thinking about energy.


Rising basketball in a pool scenario


where
does the energy come from?

W
hen considering a basketball floating upward from the bottom of a swimming pool, many
learners readi
ly identify several important aspects of the energy story associated with this
physical scenario.
The kinetic energy of the ball is increasing
or leveling off
as the ball moves
upward.
The gravitational energy of the ball is also increasing as the ball moves upward. In
addition, many learners recognize that the thermal energy of the ball and water must also be
increasing as
the
ball
moves through

the water
. Tracking energy in this scenario leads naturally
to the question of where all this energy is coming from. When thinking about this source of the
energy most learners will recognize that
buoyancy

plays a central role in explaining where the
ener
gy is coming from. This connection then naturally leads to challenging questions. Is
buoyancy

a force or a type of energy? If
buoyancy

can be a type of energy, is it a new energy
form or is it related to an existing energy form?
These questions challenge learners to
distinguish between force and energy and to consider the way in which energy forms should be
categorized.
Typically
small groups of
participants in our workshop will recognize that
buoyancy
is more correctly des
cribed as an interaction between objects and, therefore, a force.
They also will recognize that buoyancy does not seem to be a

type of energy that is located in the
ball. They might spontaneously
,

or
after

an instructor prompt
,

consider the
change in loc
ation of

the water as a result of
rising

ball.

‘Where does the water come from that fills the space the ball
leaves behind?


In this way, they can recognize that
,

while there is additional energy associated
the submersion of
buoyant

objects, the additional energy can
logically related to a form with
which they are familiar, namely the gravitational energy of the water/Earth.


Goals for
learner

engagement with energy scenarios


In our
workshop with teachers we have explicitly attempted to

provide teachers with
flexible tools for representing energy,
to
build a culture of negotiated scientific language and
to
present

multiple scenarios which problematize the energy conservation princ
iple. Two primary
content goals of our workshops are that:




teachers become more likely to rigorously attend to energy tracking when analyzing
specific energy scenarios.




teachers become more likely to use diagrams constructively to
track

energy
in specific
scenarios.


We think these goals are also very relevant to all learners who need
a flexible and
rigorou
s
model for engaging novel energy concepts.
By flexible
we

mean that the model can be
applied in to a wide range of en
ergy scenarios and questions. By rigorous
we

mean that the
model allows the learner to rule out certain possibilities and refine their questions.

In order to
study teacher growth in these dimensions we have adminis
tered
assessment
s before
and after we
work with them to develop representational tools and strategies for tracking energy. The
following is an example question from one of these assessments.


Lowering a Bowling Ball

-

A person carefully lowers a bowling ball from eye level to wa
ist
level. During this motion the bowling ball moves downward at a slow,
constant

speed.


(a) Describe what is happening with energy during this process. If you aren’t completely sure
what is happening with energy, describe what you know and feel free
to speculate when you
are uncertain. Please feel free to include diagrams.


(As you go, write down questions that you ask yourself and need to answer in order to
provide a reasonably complete description of the energy processes involved. Please write
these questions in the box at the bottom of this page.)


The lowering scenario was chosen based on the idea that learners who carefully attend to energy
tracking will likely struggle with the question of where the energy goes. Gravitational energy is
decreasing, chemical energy is presumably being ‘used up’ and

the kinetic energy is not
changing. The idea that all of the lost gravitational energy and chemical energy could be
transformed into thermal energy is counterintuitive for many learners as we will show below.

The pre
-
test of this question was administere
d at the beginning of a two
-
week workshop
for secondary science teachers in the summer of 2012. The post
-
test was administered at the
beginning of the second week of the workshop. During the intervening week participants had
been introduced to Energy The
ater, Energy Cubes and Energy Tracking Diagrams. They had
worked through several scenarios including a scenario involving raising a bowling ball at
constant speed. We had not yet considered the lowering scenario as a part of class instruction.
We wanted

to offer them the option of drawing diagrams but not to im
ply that diagrams were
required.
A total of 22 teachers in our workshop completed both the pre and post
-
tests.


Resu
lts


attending to energy tracking

The question asked the participants to ‘
describe what is happening with energy
’ as an
effort to encourage energy tracking. Nevertheless, on the pre
-
test, only 4 of 22 participants
provided answers which demonstrate
d an effort

to identify
the ending form and location of the
energy
. Of these 4, 3 cited that energy was transforming into thermal energy but did not clarify
whether this increase of thermal energy was
incidental or critical to the energy story.
Only one
participant articulated a concern over where the energy was going. She asked ‘Is kinetic energy
increasing if it isn’t accelerating?’ Several participants cited work being done on the bowler but

did not track the energy associated with that work to the bowler.

On the post test, 18 of 22 participants
explicity focused on where
and into what form
the
energy went

in their response. Of these, 5 gave a clear answer that the energy was transformed
into thermal and the remainder expressed their inability to figure out where the energy was
going. The transition in the participants


inclination to track energy can be m
ost clearly seen by
following individual participants.

One participant summed up her energy analysis in her pretest
by writing,


“The energy … must have been transferred to the bowler as he lowered the ball. Also, the
energy was transferred from potentia
l energy to kinetic energy while moving.”


While she is clearly cognizant of energy forms and transfers she does not follow the energy when
it is transferred to the bowler. One week later the same participant writes a lengthy inquiry into
the energy p
rocess which includes an energy tracking diagram. She circles the gravitational
energy that is originally in the ball and asks,
“converted, but I don’t know where or to what?”

She describes the increase in thermal energy in the air but also
ap
parently decides

that this
increase in thermal energy cannot be sufficient to account for the energy decreases in her
analysis
.
“I still have questions about gravitational energy units in the ball. I can’t track
them?”

Many other participants
articulate an in
ability to account for where the energy goes.
Another participant writes,



If a ball is being lowered and decreasing the gravitational energy, where is that energy going if
it is moving at a constant rate? Can’t go back to chemical, so
is it lost to the environment as
thermal? Or does

it become “stored”???? IDK!



And another participant writes,


“In this case, the potential energy becomes....? Kinetic energy in the hands? But the hands
don’t speed up. Thermal energy? Certainly
not all of it.... Maybe as it is converted into kinetic
energy , it is then moved into the arms as elastic energy at a constant rate so there is only one K
present in the ball at all times. The increasing elastic energy represents the effort of to hold t
he
ball by muscle increasing over time. But is that force?”


Even the participant whose pre
-
test response most completely addressed the question of
where the energy goes demonstrated an increase in their scientific questioning and efforts at
sense making.

On their pre
-
test they correctly identified that,

“KE was turned into (thermal?
elastic?) energy in the muscles.”

On the post
-
test,
th
e

question

raised a more elaborate and
refined set of questions for this participant.


“GPE
must

go somewhere
-
>

into arm is only choice
but

KE of arm does not increase
because arm speed is constant... Definitely
does

not

get reclaimed in stored chem. PE in muscles
(like a hybrid with regenerative braking... How do arm muscles
receive

energy from an external
sourc
e (
not

through digestion, ATP, etc...)? Go up, muscle PE to ball gravitational PE make
some sense but going
down
, loss of GPE becomes ….? Don’t know.”


This
participant’s original response
seems
satisfactory to us
and to the participant. They
apparently
recognize that
the

ar
m

muscles
receive

energy’

yet express
uncertain
ty

about how to
describe or account for

this accumulated energy in the muscles. Nonetheless, on their post
-
test
the
y

raise new questions about their analysis of the energy transfers and transformation. They
articulate

a
reclaimed energy model
and
intuitively rule it out
.
They
make a scientific
comparison with the lifting scenario
appear to decide that while the motions are simply reversed
the energy story cannot simply be reversed. If it could then muscles would
be

act
ing like a car
with

regenerative braking.

We infer that
they are making use of the intuition that we cannot ‘re
-
charge’ our muscles by lowering bowling balls.


Results


using diagrams as reasoning tools

We also observed an increase in both the prevalence of diagrams in participant responses
and the apparent use of diagrams as reasoning tools when analyzing this scenario. On the pre
-
test only 5 of 22 participants included a diagram in their answer. Of th
ese 5 diagrams,
we
classified three as being primarily used to illustrate an idea

(Figure
4
).






Fig.
4.
Examples of diagrams that are primarily used
to illustrate an idea.

Fig
.

5
.
An energy
diagram which was used
to arrive at a self
-
consistently analysis of
where the energy went.



A week later we see a dramatic increase both
in the prevalence of diagrams and in the degree to
which diagrams were used as
tools for tracking
energy
. 16 out of 22 participants included
diagrams in
their analysis and of these,
12 were clearly using these
diagrams
as
tools for tracking the energy in this
scenario
.
Figures 5 and 6 shows

examples of two such
diag
rams.












Fig.
6. An energy

diagram which was successfully used by a participant to refine their questions
about where the energy went.


We think that the complexity and evidence of progressive refinement in
these diagrams suggests
that they are being used constructively by these participants in their efforts to figure out what is
happening with the energy in this scenario.


Summary of preliminary findings

In this preliminary study we saw a consistent increase in the degree to which participant
responses raise ideas and questions about where the energy goes. We also observed an increase
in the prevalence and constructive use
of diagrams. There are a number of possible explanations
for these changes:




The in
-
class analysis of a similar scenario involving raising a bowling ball may have
primed participants for engagement with this scenario



Participants may have become
acculturated

to the kinds of questions and representations
that were more highly valued by the Energy Project instructors



Participants may have progressed in their ability and/or inclination to track energy



Participants may have progressed in their ability to use
energy tracking
diagrams
constructively



We suspect that all of these factors influenced the changes that we observed in participant
responses. Nevertheless, this preliminary study demonstrates tha
t the way in which participants
document their analysis of a challenging energy scenario changed significantly as a result of
parti
ci
pating in a single week of professional development. Furthermore, we feel that these
observed changes correspond to fundam
ental goals for learner engagement with energy concepts.


IV)
Developing a pedagogically accessible model for energy use, usefulness and degradation
that makes sense to students and is widely applicable.


At some point in their
schooling, most

learners encounter a model for energy that is
transferred and transformed but is always precisely conserved
. In the popular press
,

citizens
encounter a resource model in which energy is bought and sold, used and wasted, and can be
conse
rved only through human efforts. If learners merely adopt a science classroom definition
for energy conservation which they cannot connect with their understanding of energy that can
be used well or wasted then they will be less likely to apply energy mod
els from the science
classroom to the energy issues that they care about.

The challenge of constructing an accessible model for energy usefulness remains an
unanswered question for us. This model must include the ways in which energy degrades but
also in
tegrate naturally with the conservation model. In addition to the ‘standard’ model of
irreversibly increasing entropy, the literature suggests models for energy degradation which
include energy spreading (Leff, 2012) and entropy as freedom (Amin, 2012).
It seems that an
appropriate model may need to include both objective and subjective components.
Consider the
way in which a light

bulb transforms electrical energy into thermal energy in a lighted room.
There is an objective sense in which the energy is

degraded because there is no way to reverse
this process and transform the thermal energy completely back into electrical energy. There is
also a subjective sense in which the thermal energy in the room is more useful if
the occupant
wants the room warmer and less useful if the occupant wants the room cooler
. As one of the
teachers in our workshops pointed out,
“The heat from a light

bulb isn’t wasted if you are a chick
in an
incubator.”


We
ex
pect
that

a

model for energy usefulness

which can empower learners to
address
socio
-
politically

challenging energy issues will integrate object
ive

scientific principles
with subjective normative

priorities.
We also hope to identify
specific scenarios which catalyze
learner engagement with concepts relating to energy usefulness.


V. Conclusions


We are working with teachers to build a model for energy that is precisely conserved
while it is often degraded both objectively and subject
ively.
We
hope to empower teachers to
constructively
engage with energy questions
using
flexible rep
resentational strategies within

c
lassroom learning communities that are characterized by
negotiation, consensus building and
s
ense
-
making. In the preceding pages we have
described instructional strategies which we
have
found to be effective in summer
Energy Project
workshops
for teachers.
We have found that t
his
approach encourages teachers to
represent, negotiate, and
refine their energy understanding
through

engagement with conceptually challenging energy scenarios.
We have shown
preliminary evidence that teachers become more likely to
rigorously attend to energy tracking
and

use diagrams constructively to track energ
y in specific scenarios.

We anticipate that through
empowering teachers to constructively engage with their own energy questions we will also
empower them to facilitate similar engagement on the part of their own students.
In
collaboration with Facet Inn
ovations (www.diagnoser.com) w
e are a
lso developing web
resources to

help teachers

adapt Energy Project instructional strategies in their classrooms

and
to
support formative assessment practices in the context of energy
.
Many
of the
teachers
from our
summer workshops
have
anecdotally

reported
increased engagement with energy questions
among their own students but we have not done a systematic study.






References


Amin
, T. G., Jeppsson, F., Haglund, J., & Strömdahl, H. (2012). Arrow of Time: Metaphorical
Construals of Entropy and the Second Law of Thermodynamics.
Science Educati
on, 96
(5), 818
-
848.


Close, E. W., Scherr, R. E., Close, H. G., & McKagan, S. B. (2011). Development of proximal
formative
assessment skills in video
-
based teacher professional development. Paper presented at
the 2011 Physics Education Research Conference.


Close

H. G.
, DeWater

L. S.
, Close

E. W.
, Scherr

R. E.
, and McKagan

S. B.
(2010).

Using The
Algebra Project method to
regiment discourse in an energy course for teachers
,
Physics
Education Research Conference Proceedings
.

Portland, Oregon. 9
-
12
.


Close, H. G., & Scherr, R. E. (2011). Differentiation of energy concepts through speech and
gesture in interaction. Paper pres
ented at the 2011 Physics Education Research Conference.


Harrer, B. W., Scherr, R. E., Wittmann, M. C., Close, H. G., & Frank, B. W. (2011). Elements of
formative assessment in learners' discourse about energy.

Paper presented at the 2011 Physics
Education Research Conference, Omaha, NE.


Kraus

P. A.

and Vokos

S.

(2011).


The role of language in the teaching of ene
rgy: The case of
'heat energy.'

Washington State Teachers' Association Journal
.


Leff
, H. S. (2012). Removing the Mystery of Entropy and Thermodynamics
-

Part I.
Physics
Teacher
,
50
(1), 28
-
31.


McKagan

S. B.
, Scherr

R. E.
, Close

E. W.
, and Close

H. G.

(2011),
Criteria for Creating an
d
Categorizing Forms of Energy,

Physics Education Resear
ch Conference Proceedings.

Omaha,
Nebraska.
279
-
282
.


Moses, R.P. and Cobb

C.E.
(2001).

Radical Equations: Civil rights from Mississippi to the

Algebra Project
.
Boston, MA: Beacon Press
.


Podolefsky
, N.S. and N.D. Finkelstein, Analogical scaffolding and the learning of

abstract ideas in physics: Empirical studies. Physical Review Special Topics
-

Physics

Education Research, 2007. 3(2): p. 020104.


Scherr, R. E., Close, H. G., Close, E. W., &

Vokos, S. (2012). Representing energy. II. Energy
tracking representations. Physical Review
-

Special Topics: Physics Education Research, 8(2),
020115 020111
-
020111.


Scherr, R. E., Close, H. G., McKagan, S. B., & Vokos, S. (2012). Representing energy.

I.
Representing a substance ontology for energy. Physical Review
-

Special Topics: Physics
Education Research, 8(2), 020114 020111
-
020111.


Scherr

R. E.
, Close

H. G.
, Seeley

L.
, and McKagan

S.

(2012,
February
)
Representing energy
transfers and
transform
ations
.
Poster

presented at the American Association of Physics Teachers
Winter Meeting
, Ontario, California.


Schwartz, D.L. and T. Martin, Inventing to prepare for future learning: The hidden

efficiency of encouraging original student production in statistics instruction. Cognition

and instruction, 2004. 22(2): p. 129
-
184.


Schwartz, D.L., Why dire
ct instruction earns a C
-

in transfer, 2009: Northwestern Center

for Engineering Education Research.