4.) 236.6 cm3 partially hydrogenated tallow triglyceride
There are 10 ingredients in all, followed by a set of scientifically
precise instructions. (Sample: "To a 2-L jacketed round reactor vessel
(reactor #1) with an overall heat transfer coefficient of about 100 Btu/F-ft2-hr,
add ingredients 1, 2 and 3 with constant agitation.") The recipe ends
with this admonition: "P.S. Don't try this at home." There are more challenging
activities where that came from. A lot more.
When Teaching K-8 paid a recent visit to Menelly's classroom at Dodd
Middle School in Cheshire, Connecticut, his students were nearing the
end of a four-day project that involved rating household products. The
students had formed teams of from one to five and had chosen - one product
to a team -- from a long list on the chalkboard that included such items
as glass cleaners, detergents, glue, degreasers, scouring pads, sweeteners,
butter and fish food.
Once the products were chosen, the kids were pretty much on their own.
First, they were asked to select three or four brand names; they then
had to identify three of the products' variables. Four boys who were investigating
anti-bacterial soap, for example, settled on cost, smell and germ-killing
power as their three variables.
But the challenge was just beginning. The teams were then expected to
devise and carry out tests for all three variables. Cost and smell are
relatively easy, but how about germ-killing power? The boys set up cultures
of chicken broth, added soap and, a few days later, used a microscope
to examine the cultures for bacterial growth.
Testing variables. Here are two more bright ideas the kids came up with
to test variables:
* A team investigating the carbon dioxide content of leading brands of
soda put balloons over the tops of cans, shook the cans, which released
the gas and noted the size of the balloons.
* A team investigating the staying power of perfume sprayed three colored
balloons with perfume, hung them on a tree outside the school for six
hours and then polled other students to see which perfume was the strongest.
Where was Menelly while all this was going on? In constant motion around
the classroom, that's where. When students need encouragement or a few
helpful suggestions, he's never very far away. But even so, essentially
it's still the kids' show.
Constructivist approach. Here's what Menelly has to say about giving
the kids a large piece of the action. "I've been modifying instruction
in my classroom to center on a more constructivist approach. I'm not interested
in the approach because it seems to be the current trend, but because
it really seems to suit the way middle school science students seem to
learn.
"I recently ran a wave physics activity, where students were encouraged
to design their own wave physics experiments with materials I placed at
different stations throughout the room. I was encouraged to see students
assembling some very effective and simple science experiments.
He continued, "When I questioned students about what they were doing,
they were able to make some pretty meaningful connections between their
own experiments and some of the abstract ideas encountered in class discussions.
That's an outcome I sometimes don't see when students run through prepared
'cookie cutter' labs."
Menelly has also been experimenting with student-centered research opportunities.
He cited a recent activity where students were grouped by interest, not
ability, to research one of five theories of atomic structure.
"I wanted them to build their own foundation for the study of matter
and chemistry, so I had them explore the fundamental theories of atomic
structure," he said. "Students went online for research data, pored over
science reference materials and even waded through some philosophical
references, studying Democritus and the Greek theories of the atom."
Woven into all this do-it-yourself science is an assessment process
that often encourages the eighth graders to be their own judge of how
they're doing. Following the testing of household products, for example,
students critiqued each other's experiments and also wrote about what
they thought they could have done better on the project and what they
did that no one else did. (One student noted that he had sounded out the
school nurse about a certain brand of anti-bacterial soap.)
Special needs. Menelly teaches four sections totalling 97 students. Joining
him for some of his classes is Janet Johnson, an instructional assistant
who is also a certified teacher. Menelly also keeps in close touch with
the school's special ed teachers. This is important, he noted, since 23
of his students have special needs. Also, many of these students have
never before been mainstreamed into a regular science class.
Other approaches. It's not one science experiment after another in Daniel
Menelly's classes. Throughout the year, he comes up with other approaches
to science -- through language arts and social studies, for example. Later
this year, he'll team up with a language arts teacher to teach kids about
the Holocaust. In language arts, students will read The Diary of Anne
Frank; in science, they'll study German scientists who were persecuted
by the Nazis.
"I'm also reinforcing some of the more practical issues in science, like
building a working science vocabulary," Menelly said. "The kids recently
had a fun time with an activity I call 'The Living Puzzle.'
"I randomly distributed 'Living Puzzle' pieces to my students. Some had
science vocabulary terms, others had graphs and schematic diagrams depicting
the vocabulary terms. The students were then asked to locate the 'matching'
image or word and sit next to the student possessing it.
"Once everyone was seated, I asked students to explain why they chose
certain partners," Menelly said. "In pairs, they explained and described
their terms in a language their peers could understand. My role was really
a small one. I simply set up the puzzle and ushered students off in different
directions, encouraging them to ask each other if their pieces fit together.
"It was such a simple, almost elementary activity, but I was impressed
with the students' mastery of the new science terms, and I was able to
avoid the rote treatment of this material that sometimes turns kids off."
Heart of the matter. Menelly's science projects don't get any easier
as the school year rolls on. Soon, his students are going to be asked
to solve an insulation problem that goes like this: A living heart is
offered by a donor on the west coast to a heart transplant patient on
the east coast. Design a container that will allow the heart to remain
cool while being shipped.
What do the students think about taking charge of their science education?
When Teaching K-8 questioned them, they said things like, "We're having
fun," and "It beats just listening." But that day, one action (or perhaps
it was a non-action) spoke louder than words. The bell had rung and all
of the students had left for lunch, except for two girls engrossed in
their project.
"Did you see those two girls?" Menelly said later. "They have friends
they meet for lunch and usually they're the first ones out of the door.
But today, they were all wrapped up in science." He stopped and thought
about it for a moment, and then said, "I'm really encouraged." Need to
check out a chemical element? Just take a look at the periodic table on
the wall.
AUTHOR:
IAN ELLIOT
.
SOURCE:
Teaching PreK-8 28 34-8 Ja '98 The magazine publisher is the copyright
holder of this article and it is reproduced with permission.
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