CECsci.143


TITLE:    POTATO CHIP CLASSIFICATION

AUTHOR:   Janet C. Duncan, Meadow Glade School
          Battle Ground, WA

GRADE LEVEL:   Appropriate for grades 5-8.

OVERVIEW:  The purpose of this activity is twofold.  Used at
the beginning of the year, it introduces the structure and
function of a dichotomous key preparatory to asking students
to identify plant and animal specimens.  It also reinforces
the idea that there are many "right" answers in science.

OBJECTIVE(s):  Students will be able to:
1.  Classify "specimens" (in this case, potato chips)
    according to observable characteristics.
2.  Prepare a "key" showing their classification system.
3.  Use their key to identify a specimen.
4.  Recognize the validity of classmates' classification
    systems.

MATERIALS/RESOURCES:
1.  Eight bags of potato chips selected for differences
    in observable characteristics (i.e. color, texture,
    brand name, flavoring, etc.)
2.  Chalkboard or overhead projector for recording class
    key.
3.  Representative samples of each type of chip in
    labeled plastic bags. (Quantity determined by number
    of student groups.)
4.  Paper and pencils for student group recording.

ACTIVITIES AND PROCEDURES:
1.   Display bags of potato chips and discuss their
     similarities and differences.
2.   Ask volunteer to divide chips into two groups using an
     observable characteristic (i.e. flavored/not flavored).
3.   Record results of first division.
4.   Continue to divide groups of chips, using a different
     characteristic each time, until only one bag of chips
     remains in each group.  Continue recording results.
5.   Using the class key, identify "unknown" chips.
6.   Divide class into groups of four to six students.
7.   Provide each group with a sample set of chips.
8.   Ask each group to devise and test a dichotomous key
     that is different from the class key.
9.   Record and share results.
10.  Eat the chips!

EXTENSIONS:
1.  Repeat activity with other objects such as candy,
    shoes, etc.
2.  Share story of potato chips resulting from "mistake."
    ("Mistakes that Worked" by Charlotte Jones)
3.  Introduce and use plant and animal keys.


SAMPLE KEY:

                     orange    (Party Pride Barbeque)
             flavored
                     not orange (Party Pride Sour Cream)
Chips in box
                     ridges (Bell Dip Chips)
             not flavored
                     no ridges (Party Pride Potato Chips)
             ridges (Nalley's Dip Chips)

Chips in bag
                     not "gourmet" (Lay's Potato Chips)
             no ridges
                                   salted (Kettle Chips
                                             Jalapeno)
                     "gourmet"
                                    unsalted (Kettle
                                      Chips Unsalted)