The task
After a unit of study on cells, students were asked to demonstrate how diffusion
occurs and write a report about their demonstrations.
Circumstances of performance This sample of student work was produced under the following
conditions:
alone
in a group
in class
as homework
with teacher feedback
with peer feedback
timed
opportunity for revision
The work was done in a group but written up individually.
This
work sample illustrates a standard-setting performance
for the following parts of the standards:
a
Physical Sciences Concepts:
Properties and changes of properties in matter.
a
Life Sciences Concepts: Structure
and function of living systems.
a
Scientific Connections and Applications:
Big ideas and unifying concepts.
a
Scientific Thinking: Frame questions;
identify or control variables.
b
Scientific Thinking: Use concepts
from Science Standards 1 to 4.
a
Scientific Tools and Technologies:
Use technology and tools.
e
Scientific Communication: Communicate
in a form suited to the purpose and audience.
What
the work shows aPhysical Sciences Properties:
The student produces evidence that demonstrates understanding of properties
and changes of properties in matter…. The student accurately
describes the meaning of “semipermeable.”
aLife Sciences Concepts: The
student produces evidence that demonstrates understanding of structure
and function of living systems, such as the complementary nature of
structure and function in cells…. The student demonstrates
conceptual understanding of the structure and diffusive function of
cell membranes.
aScientific Connections and Applications: The
student produces evidence that demonstrates understanding of big ideas
and unifying concepts, such as…cause and effect. The student correctly
identifies an example of diffusion, ruling out gravity as an alternative
cause of the observed phenomena.
aScientific Thinking:
The student frames questions to distinguish cause and effect; and
identifies or controls variables in experimental and non-experimental
research settings. The student identifies
pore size as a variable.
The student frames her results as a series of questions and answers.
bScientific Thinking: The
student uses concepts from Science Standards 1 to 4 to explain a variety
of observations and phenomena. The student applies
elements of a
and a
in her discussion of the property of semipermeability and the process
of diffusion.
aScientific Tools and Technologies: The
student uses technology and tools (such as traditional laboratory
apparatus…) to observe and measure…phenomena directly….
The list of materials and the four parts of the procedure indicate
that the student used traditional laboratory apparatus to observe
the process of diffusion directly. The student provides
photographs of the laboratory set-ups.
eScientific Communication: The
student communicates in a form suited to the purpose and audience,
such as by writing instructions that others can follow…. The student
demonstrates effective scientific communication by clearly outlining
a procedure that other students could follow.
The student accurately
describes the meaning of “semipermeable.”
The student demonstrates
conceptual understanding of the structure and diffusive function of
cell membranes.
The student correctly
identifies an example of diffusion, ruling out gravity as an alternative
cause of the observed phenomena. 
The student frames her results as a series of questions and answers.
The list of materials and the four parts of the procedure indicate
that the student used traditional laboratory apparatus to observe
the process of diffusion directly.
The student provides
photographs of the laboratory set-ups. 
