by Joyce R. Blueford
Large structures are always built on small networks of
smaller structures. Without knowing or even thinking about the smallest building
blocks, you would miss an entire world that is just waiting to be explored!
How does one look at the microworld? It wasn’t until the
18th century that major breakthroughs in the physics of optics made the
microscope a reality and consequently a vital part of research. The discovery
that we could see smaller and smaller things by using a series of lenses led
scientists to look closer at the animal, plant, fungi, protozoan and bacterial
worlds. Non-biologists started to look at other materials, and realized that
this could help illuminate the nature of all kinds of things. The microscope
became humanity’s "new eyes" to look into the smallest mysteries of
the universe.
The Microscope and Young Children
The microscope can be taught to students as young as 4 or
5 years old. We have found letting young children experience the
"tiny" world helps them understand that it’s really there. Then,
when you then tell them that protozoa or bacteria cause diseases, it makes more
sense that things they can’t see with their eyes can impact our
"large" world.
In the last 15 years we have observed thousands of
children using a wide variety of microscopes. We wanted to determine what type
of microscopy is appropriate to which ages. Many teachers had opinions, but
there was no scientific study that we could find. So we decided to evaluate
microscopy for ourselves.
We began in the lower grades by using thin sections of
cells, tissues, and protozoa, asking children what these cross sections
represented. Children less than 9 years old had a very difficult time
understanding how a thin slice of an organism related to the whole organism.
Students would become restless and bored with these labs. When we tested for
comprehension, they did not fully understand the lesson.
We realized that using transmitting light microscopes was
difficult for a young mind to interpret. This corresponded to the results of
another study, which found that cross sections of the Earth could not be fully
interpreted by students under the 4th grade.
However, once we started to use reflected light
microscopes (dissecting microscopes), students were much more attentive and got
excited. Looking at the compound eyes of flies, fabric, or a computer chip was
fun and easy for them to understand. They were able to add more information
easily to their prior knowledge.
We concluded that children under 10 learned best by
observing and understanding more detail on objects already familiar to them.
Later, as students mature in their scientific investigation, they can begin to
understand thin sections.
Even as late as the 8th grade, however, students still
preferred the dissecting scope over the transmitting light microscope, We found,
in a study of 7th and 8th graders, that students were willing to use the
transmitting light microscope for lessons that required it, like comparing
organs from different small organisms, and they understood the concepts taught.
Given a choice, though, they still preferred the reflected light microscope.
They loved looking at hair fibers, fingerprints, tree bark, insects, and
anything they could put the microscope over.
A Sturdy, Inexpensive Microscope
Over the last 15 years of developing strategies for
teaching microscopy to K-8 students, we have tried a wide variety of
microscopes. We finally feel that we have not only the curriculum, but an
affordable microscope (the Swift GH) that will make an early introduction of
microscopy feasible across the country.
The Swift GH microscope is optically very simple, and the eyepiece and objective are
designed to use regular light to see an object. It is easy to use for sand,
letters or leaves (opaque objects), but can also work well for fleas, brine
shrimp and thin sections.
The Swift GH is lightweight, sturdy and can easily be used
outside. Plus it comes with a lifetime guarantee from Swift Instruments.
The only other similar scope within an affordable price
range is the Brock Magicscope. The optics are not as good and the stage is not
removable, which makes it difficult to use for some specimens. More expensive
dissecting scopes are also useable.
The labs that we eventually designed all revolved around
the Swift GH type model because of cost and usability by the students. We used
the scopes to teach about optics as well as for examining biological and
geological specimens. About one third of our labs in the Integrating Science,
Math, and Technology Program use the Swift GH.
A Classroom Solution
Once you have a quality microscope, however, you still
need an age-appropriate curriculum and workshops for teachers. Working with
Alison Swift of Swift Instruments, Math/Science Nucleus (MSN) has taken its most
popular hands-on microscope lessons from the Integrating Science, Math &
Technology program, added in some new ones and bundled them all together
with the Swift GH to create the new "Microscope Trunk."
This trunk includes 5 Swift GH microscopes, a teacher’s
manual and a complete set of supplies for each microscope for 8 different
hands-on laboratories. An additional 6 lesson plans given in the manual do not
require special supplies.
The main goal of the teacher’s manual is to show how the
microscope can be used to teach different concepts in science. The chosen labs
are not only successful in the classroom, but can also give the teacher a
background on the many ways to use the computer, should the optional CD-ROM be
purchased.
The manual is divided into six chapters, all of which
include lesson plans.
Chapter 1—Overview.
How microscopes work, with a special section on the Swift GH.
Chapter 2—Physics.
Understanding the optics of a
microscope.
Chapter 3—Technology.
How microscopes are used in some industrial settings, like checking defects on a
microchip.
Chapter 4—Earth Sciences
Studying rocks and sand and monitoring water pollution.
Chapter 5—Biological Sciences
Learning how to use the power of
the microscope to teach about cells, arthropods, marine invertebrates, microbes,
and rot.
Chapter 6—Forensic Science
Solving mysteries with a
microscope using fingerprint and fiber identification.
The lesson plans are geared toward upper primary to junior
high, but can be used for lower primary. The equipment and supplies can
certainly be used at all levels to introduce the use of the microscope and the
concept of living things and structures we cannot see with our eyes alone.
However, if a teacher wants to use the microscope extensively at lower levels,
we highly recommend the purchase of our Integrating Science, Math, and
Technology Curriculum books, which outlines lessons for all grade levels.
Software to Jazz It All Up
An optional addition to the standard contents of the
Microscope Trunk is Microscope Science Templates, an interactive CD-ROM that
allows teachers to view and show to students graphic and video clips relevant to
each of the labs.
For example, if you are doing a lab on
"Microbes", and want to illustrate the different protozoa you can
"click" on a frame of a paramecium and view the video clip for 15
seconds. You would also have graphics on different kinds of paramecium, plus
text you can use for your own additional background or with the class.
This "electronic textbook" can be used on a
PC-compatible computer with a CD-ROM or with the Xerox LiveBoard. MeetingDesk
software, a simple authoring program for teachers which is necessary to access
the templates, is included on the CD.
This software helps adjust the lessons for different
degrees of proficiency on the microscope, as well as different grades. Workshops
conducted by MSN staff will illustrate how to use the material in the classroom.
Several of these workshops are scheduled for the 1996-97 school year. Contact us
for more information.
Watch our next newsletter for details of our March, 1997
release.
Together the Swift GH Microscope, the hands-on material,
the manual and CD will help K-8 teachers really teach beginning
microscopy—easily and correctly.