Curriculum Resources/Demonstrations

Psymple Statistics for Psychology

Joyce Hylton, West Springfield High School, Springfield, VA and Pam Hannah, Thomas Jefferson Science and Tech, Alexandria, VA

Concept:

Have you ever wondered which brand of chocolate chip cookies gives you the most chocolate chips per cookie? Many manufacturers advertise that their cookies have the most chips. Through this experiment students can define a problem, operationally define terms and a procedure for measurement, state hypotheses and get some experience with simple statistics.

Instructions:

Define the problem: Are there the same number of chips in each type or brand of cookies? Which one has more and how do you determine this?

Define operational terms and a procedure for measurement: It is necessary to define what a chocolate chip is and how much of it needs to be there in order to be counted.

State the null hypothesis: There will be no difference in the number of chocolate chips found in each cookie.

Have students bring different brands or types of chocolate chip cookies to class. (Creativity counts-they can even bring homemade cookies.) Have each student who brings in a different type of cookie take the top one out and count the number of chips.

Prove or disprove null hypothesis? Since there is a difference each time, the null hypothesis is disproven.

State an alternate hypothesis: Whichever cookie brand had the most number of chips in the first sample will have the most number of chips of all the cookie brands.

Data collection: Divide the class into groups of equal size depending on the number of cookie brands there are and sit at a table with that bag of cookies. Each student should randomly select a cookie from the bag and count the number of chips. You could also generate a random sampling procedure to determine which cookies are counted.

Results and discussion:

1. What is the mean score for each type of cookie?
2. What is the mean score for all cookie types added together?
3. What is the range of chips for each type of cookie--What is the median number of chips? What is/are the modal numbers?
4. What is the variance per cookie brand? For all brands?
5. Plot a curve on the board for the normal distribution of chocolate chips?
6. What is the standard deviation?

The above activity was originally published in the Nov/Dec 1995 issue of The Psychology Teacher Network. The activity is reprinted here with the permission of the Education Directorate of the APA. Further publication of the activity is not permitted without the express written consent of the Education Directorate.

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