Open Ended Laboratory
Open Ended Laboratory
Open Ended Laboratory
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The traditional high school physics course consists primarily of lecture-style classes that are sometimes accompanied by laboratory exercises. In recent years, there have been
significant changes in the teaching of physics toward greater
conceptual understanding.1 But research has suggested that
laboratory experiments fall short when it comes to enhancing
student learning with understanding.2 According to Hackling
and Garnett, many high school physics students have been
found to have poorly developed skills of problem analysis,
planning and carrying out controlled experiments, basing
conclusions only on obtained data, and recognizing limitations in the methodology of their investigations.3 HaagenSchuetzenhoefer suggests that ritualized and restricted lab
procedures leave hardly any opportunity for students to
engage individually, and frequently result in poor quality lab
reports and moderate learning processes.4 Staer, Goodrum,
and Hackling suggest that poor problem-solving skills might
be related to the extent to which laboratory work is open to
inquiry. In closed-ended labs, the teacher selects and prescribes the problem, the apparatus to be used, the procedures,
and expected outcomes. In an open-ended lab, many of these
decisions are left to the students conducting the inquiry. They
found that substantial teacher opposition to open inquiries
is founded primarily on the belief that students cannot work
without procedures set by the teacher.5 While the teachers
surveyed felt that open-ended inquiry-based laboratory investigations would be beneficial for their studentsas they
would promote greater student interest, ownership, motivation, problem-solving skills, creativity, and positive self-esteemthey also thought that implementation and evaluation
of such investigations would be difficult, especially with lower
DOI: 10.1119/1.4849147
achieving students.
Researchers have discussed some of the benefits of openended laboratories in university-level physics courses. Nissani, Maier, and Shifrin state that hands-on experiences
help students to assimilate theoretical concepts they are
introduced to after a lab.6 The University of Maryland Physics Education Research Group has established a teaching
resource known as Scientific Community Labs (SCL), which
are labs designed to give students the experience of participating in a model of a realistic scientific community. In the
SCL, students are given the opportunity to explore problems
through experimentation. They work in groups to design an
experiment, carry it out, analyze it, and present their results
for discussion with the other students in the class.7 In her
doctoral dissertation, Lippmann found that the time students
spent sense-making in the SCL was five times more than in
traditional labs and that these students also adopted more
productive behaviors as a result.8 Using an Investigative Science Learning Environment (ISLE), Etkina, Murthy, and Zou
demonstrated student improvement in the abilities to design
experiments, choose productive mathematical procedures,
communicate the details of the experiment, and to evaluate
the effect of experimental uncertainties.9 In addition, Etkina
et al. determined that students who consistently engaged in
designing their own laboratory procedures outperformed
the non-design groups while working on novel experimental
tasks.10 Duggan and Gott pointed out that procedural understanding, gleaned from open-ended investigations, might be
just as important as conceptual understanding,11 while Karelina and Etkina found that students developed a scientist-like
approach to experimental design when they designed their
own labs.12
I concur with these conclusions, as my colleague Dave
Carlgren and I have successfully implemented open-ended
inquiry-based laboratory investigations in our high school
physics laboratories. The following is a description of the evolution of our lab program.
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10.
11.
12.
13.
14.
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Theory
Part I: Reflection.
A concave (or converging) mirror is used in this portion of the
experiment. These mirrors can produce two types of images:
Real images. A real image is such that the light reflected from
the mirror is actually present at the spot the image appears. If
one was to put a screen at this location, the image would be
visible on the screen. The ray diagram below illustrates this
phenomenon. For a real image to occur, the object must be
outside the focal length of the mirror (which is equal to half the
curvature for a spherical mirror).
There is a third possibility as wellno image. When an object
is placed at the focal point, the reflected rays are parallel, and
thus no image is formed.
Both mirrors and thin lenses can be described with the equation
where f is the focal length of the mirror, di is the images distance from the mirror, and d0 is the objects distance from the
mirror. As well, this equation can take into account phenomena
such as virtual images by accounting for signs. The sign conventions for this equation are:
focal length; f is positive for a converging mirror/lens and
negative for a diverging one.
object distance is always positive within the scope of this
course.
image distance; di is positive for a real image and negative
for a virtual image.
Fig. 2. A student-generated theory section.
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for answers to a given problem arising in the lab, they did not
look for the big answer to the experimental questions, but
instead only sought guidance on how to move through a specific difficulty. In other words, they did not wish to be spoonfed, and wanted to continue discovering on their own.
Implementing open-ended labs can help students acquire
science process abilities that allow them to construct models
based on observational data, design experiments, solve openended problems, and work collaboratively with their peers.
However, the development of these abilities can be frustrating
for students as they struggle with problems that do not have
one correct approach or solution.13 During inquiry-based
investigations, many students feel overwhelmed, do not know
where to begin, and long for the more familiar lab where the
procedure is written out for them and they simply have to
follow instructions. The experiments take a longer period of
time, and teachers often have difficulty relinquishing control
in the lab.14 Some teachers might be reluctant to invest this
time, as they feel that frontal teaching and closed-labs might
be more efficient in covering the curricular objectives. Battista pointed to the myth of coverage wherein teachers believe that if a topic is taught, it is learned.15 We readily admit
that we were initially also concerned about the time and patience required to conduct open-ended labs. But as more experiments unfolded, and as our students got used to this style
of investigation, we found that it was an effective way to address many curricular objectives. Engagement in open-ended
labs generally instilled a greater sense of interest in students
with respect to the material under investigation.
If they are to succeed, open-ended labs require that students receive significant support and encouragement from
their teachers. This is particularly true when students are just
introduced to this new style of inquiry. When we first implemented this style of laboratory experiment, we also allowed
students to resubmit lab write-ups that were completed poorly. We would provide the students with specific feedback and
instructions for how to alter their work in order to improve
it. Later on, we found that this was not required as students
became very familiar with the open-ended expectations.
They came to understand that the final results of an experiment mattered far less than an insightful interpretation of the
results and the experiences gained through the investigative
process.
The process of implementing open-ended labs not only
changed our students, but also provided transformative
experiences for us as teachers. Providing less direct instruction in the lab made us realize just how averse we were, even
if subconsciously, to allowing students to problem solve on
their own. Instead of providing students with direct and immediate answers to their questions, we learned to question
students in a manner that led them to discover the answers.
We have found that there is no substitute for actual discovery,
and that the greatest learning opportunities exist in moments
when students discover for themselves. Our open-ended labs
provided the opportunity for our students to experience, in
a more authentic way, what it is like to be an experimental
physicist.
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Acknowledgments
The author would like to acknowledge the critical role
played by his friend and colleague Dave Carlgren in the creation and implementation of the open-ended lab activities.
Special thanks also goes to Dr. Moses Renert for his assitance in the preparation of this manuscript.
References
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Aaron Szott has a BSc and MSc in physics as well as a BEd from the
University of Calgary. He has been teaching high school physics for nine
years and is very passionate about inquiry-based learning in both physics
and mathematics.
szott@rundle.ab.ca
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