Grades 912 Performance Task
Contributed by: New York State Education Department (NYSED)
Developed through University of Buffalo and NORC (1991)
Description:
Students will design and carry out an experiment to
test the effects of two variables (time and concentration) on diffusion
of potassium permanganate into potato cubes.
This task assesses students' abilities to state a
hypothesis, develop procedures for investigation, develop a plan
for recording and organizing observations and data, observing and
collecting data, drawing an appropriate graph, and drawing consistenc
conclusions based on scientific principle.
This task is designed to take students approximately
80 minutes to complete  30 minutes to complete Part A (Experiment
Design) and 50 minutes to complete Part B (Experiment Report).
Overall Task Content Area:
 Life Science
Specific Knowledge Areas:
 The cell
Performance Expectations:

conducting investigations

using equipment

gathering, organizing, and representing data

formulating conclusions from investigational
data

applying scientific principles to develop explanations
and solve new problems
National Science Education Standards:
12 A SI 1: Abilities necessary to do scientific
inquiry: Grades 912
1.2 Design and conduct scientific investigations. Designing
and conducting a scientific investigation requires introduction
to the major concepts in the area being investigated, proper equipment,
safety precautions, assistance with methodological problems, recommendations
for use of technologies, clarification of ideas that guide the inquiry,
and scientific knowledge obtained from sources other than the actual
investigation. The investigation may also require student clarification
of the question, method, controls, and variables; student organization
and display of data; student revision of methods and explanations;
and a public presentation of the results with a critical response
from peers. Regardless of the scientific investigation performed,
students must use evidence, apply logic, and construct an argument
for their proposed explanations.
1.3 Use technology and mathematics to improve
investigations and communications. A variety of technologies, such
as hand tools, measuring instruments, and calculators, should be
an integral component of scientific investigations. The use of computers
for the collection, analysis, and display of data is also a part
of this standard. Mathematics plays an essential role in all aspects
of an inquiry. For example, measurement is used for posing questions,
formulas are used for developing explanations, and charts and graphs
are used for communicating results.
1.4 Formulate and revise scientific explanations
and models using logic and evidence. Student inquiries should culminate
in formulating an explanation or model. Models should be physical,
conceptual, and mathematical. In the process of answering the questions,
the students should engage in discussions and arguments that result
in the revision of their explanations. These discussions should
be based on scientific knowledge, the use of logic, and evidence
from their investigation.
12 C LS 1: The cell: Grades 912
1.1 Cells have particular structures that underlie their
functions. Every cell is surrounded by a membrane that separates
it from the outside world. Inside the cell is a concentrated mixture
of thousands of different molecules which form a variety of specialized
structures that carry out such cell functions as energy production,
transport of molecules, waste disposal, synthesis of new molecules,
and the storage of genetic material.
(Use the "hot" link on the PALS home
page to check the full text of related National Science Education
Standards, if desired.)
National Council of Teachers of Mathematics:
DAP1: Formulate questions that can be addressed
with data and collect, organize, and display relevant data to answer
them:
Grades 912 l. understand the meaning of measurement data
and categorical data, of univariate and bivariate data, and of the
term variable
Grades 912 m. understand histograms, parallel box plots,
and scatter plots and use them to display data
DAP2: Select and use appropriate statistical methods
to analyze data :
Grades 912 h. for bivariate measurement data, be able to
display a scatter plot, describe its shape, and determine regression
coefficients, regression equations, and correlation coefficients
using technological tools
AL4: Analyze change in various contexts:
Grades 912 f. approximate and interpret rates of change
form graphical and numerical data
PS2: Solve problems that arise in mathematics
and in other contexts:
Grades 912
REP3: Use representations to model and interpret
physical, social, and mathematical phenomena:
Grades 912
General Instructions to the Teacher:
This task is designed to take students approximately
80 minutes to complete.
Students will be working individually during this
exercise.
Students should be ready to work as soon as the period
begins. The materials should be set out at each lab station, if
possible. A central supply area, if needed, should be easily accessible.
All supplies should be clearly labeled.
Materials for "Diffusion":
At each station students will need:
 2 firm potatoes
 Metric ruler (30 cm)
 3 small beakers
 1%, 5%, and 10% solutions of potassium permanganate (in beakers).
 Forceps
 Scalpel
 Stopwatch/clock
 Paper towels
 Experiment Display Sheet
 Waste container
 Graph paper
Advance Preparation:
None
Safety:
 Caution: When using scalpel, slice away from fingers to avoid
cuts. Handle potato cubes with forceps only.
 Be careful.
 Teachers and students should always exercise appropriate safety
precautions and utilize appropriate laboratory safety procedures
and equipment when working on science performance tasks.
Extensions/Modifications:
None
