Keeping Scientific
Inquiry Alive (The Roly Poly Lab Investigation)
Judy
Jones
Across the country the emphasis on standardized testing has continued
to grow and North Carolina is certainly no exception. We have to
give end-of-course (EOC) tests in biology, chemistry, physical science,
and physics, and have given these tests for the last several years.
This year our district decided that students have to be proficient
on these tests in order to get credit for the course. Next year
the state will put the same requirement in place for five of the
subject tests across the curriculum (including the biology test).
As teachers, we feel compelled to prepare our students for answering
these 80+ multiple choice questions and yet, we also know that good
science teaching encourages students to observe, to investigate,
and to explore ideas, behaviors that are not addressed on the EOC
tests. It has been a dilemma to figure out how to prepare our students
for these tests and still nurture scientific investigation.
One investigation, the Isopod Behavior Lab, that I use at the beginning
of the year introduces my students to the processes of science while
still addressing the North Carolina curriculum I use this lab to
teach the characteristics of the “scientific method”
and also to build interest and excitement about science. The lab
also teaches students about arthropods and about stimulus/response
behaviors. All of these concepts are in our state curriculum. The
lab is based upon an old idea that can be found in many biology
lab books. Students take some little gray roly poly isopods –
the kind that can roll up into a ball when disturbed – and
the students test their responses to various stimuli (water, sugar,
vinegar, and salt). The little isopods are easy to find (or to raise).
I can put a few slices of potato around the edge of my house and
in the morning will find many of these little critters munching
on the potato. You can take a very large plastic container with
a lid, punch holes in the side and put screening over the holes;
add some moist soil and a few of these isopods and then just keep
feeding them old vegetation and you will have an ongoing colony
to use every year.
After the students follow the very precise instructions of the
original lab, they then get the opportunity to design their own
experiment to test some other variables. We brainstorm as a class
possible variables to test. Then my students actually design and
carry out their own experiments. I find, however, that doing the
original guided lab helps the students design much better experiments.
Finally, my students write up a formal lab report based on the
part of the investigation that they have designed. I provide very
precise instructions for these write-ups in order to help my students
begin to understand the “language” of science. These
first lab reports also help me see what some of their strengths
and weaknesses are. Throughout the year, I plan various labs that
encourage more open-ended investigation and require my students
to do formal lab write-ups, thereby building their scientific thinking
skills and their writing skills.
The basic concept behind the development of this investigation
could be used for many labs that teachers incorporate into their
classes. By having the students complete the original “recipe”
lab first, they learn some of the procedures and techniques of scientific
investigation. When the students then plan their own investigation,
they can use the model of their previous experience.
To the Isopod Behavior Lab.
Please share
your ideas with me via e-mail.
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