Four days after this observation of Don’s approach to writing,
his class began a guided inquiry investigation into the nature of
density, floating, and sinking, which spanned several weeks. On
the first day of instruction, Don’s teacher, Ms. Jentzen, asked
the class to identify items that they thought would float, sink,
or sink and float. After the class created a list of items, she
asked them to identify what characteristics contributed to an
object’s sinking or floating. These conversations lasted 15
minutes, and Don’s only contribution was the nomination of a
“printer” as an object that would sink.
Next, Ms. Jentzen showed the class the CDS and asked them to
predict what would happen if she pressed on the rubber
sheeting at the top. Don volunteered, “I think when you press
down on that (rubber sheeting) the tube will go down because
of air pressure.”