| 2 | 3 |
What It Is (continued)
What did they experience and
discover while building?
the building process, students should be encouraged to test the strength,
stability, and durability of the structures they are constructing. At
the end of the building process, students should have the opportunity
to observe and discuss each other's structures. For challenges involving
strength, hang weights to test the strength
of each structure one by one, so that the students as a class can observe
what works and what doesn't.
Aesthetics is a particularly important criterion for these structures.
Aesthetics is not just how pretty a structure is, but also how it makes
the observer feel. Is the structure rigid and strong looking? Does it
have a pleasing curve to it? Is it open, light, and airy? Does it create
a feeling of tension, as if something is about to happen? Does it create
an image of movement? These garden pole structures may be considered sculptures
and looked at in those terms.
After the initial session, have the students share their free exploration
results with the whole class. Record their discoveries on the chalkboard
or chart paper; students may also record drawings of structures, observations,
and questions in science logs.
What difficulties did they
encounter and how did they resolve them?
What questions do they have
as a result of the activity?
What would they change if
they were to build it again?
The final building session is followed by weight testing, measurement,
What did they observe happening?
If their structure was wobbly,
how did they stabilize it?
Often when building cantilevers, the problem of sideways twisting arises.
These large-scale cantilevers are very susceptible to this, and many have
a strong tendency to do anything but stay straight. Look for these challenges
and ask students how they dealt with it.
Most of these cantilever structures will not hold much weight. In structures
that are tested with weights, raising questions like the following can
help the students see some of the implications of what they are doing:
How many weights can be hung
before the structure collapses?
Does it matter where the weights
Will the structure be more
likely to collapse if the weights are hung in one place or spread out?
Predict where you think the
structure will weaken first. Can that area be strengthened so that another
area will collapse first?
Questions about which poles are being bent and where poles are being pulled
out of their taped joints help locate the tension and compression elements
in these structures. Often, a long line of poles at the top of a structure
will be in tension and a long line of poles along the bottom will be in