Speculation about Annual Statistical Distribution of Seabird Carcasses

This page authored by Don Read, Bronx Community College, derived from an unknown source.
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This material was originally developed by the the National Numeracy Network
as part of its collaboration with the SERC Pedagogic Service.

Summary

Students take the data about seabird carcasses found on a Florida beach over a 12-month period, do some statistical analysis (usually in the form of a vertical bar chart), and speculate about the possible explanations for the results.


Learning Goals

  • Reinforce the usefulness of simple statistical distributions
  • Practice analytical, speculative thinking about questions for which there may not be "correct" or certain answers
  • Write clear, logically-ordered, grammatically-correct prose that convincingly interprets the data

Context for Use

This is a final exam question in a Gen Ed course (at a four-year college, obviously not Bronx Community College) called Communicating Quantitative Information. It is one of two quantitative reasoning courses that students are required to take, and they may take the course at any point in their sequence. Consequently, many students--who have successfully avoided any sort of math course throughout their college careers--take the course in the final semester of their senior years.
Students have about 20-30 minutes to complete the exercise. They may use an Excel spreadsheet or create the chart by hand.
If given as a paper to be written outside of class, this assignment would require research, citation of sources, etc.

Description and Teaching Materials

The actual question as given to the students on the exam reads as follows:


Environmentalists at a Florida beach location counted the number of dead seabird carcasses found on the beach during the twelve months of 2006. Here is their month-by-month count:

Jan, 11; Feb, 11; Mar, 12; Apr, 3; May, 1; Jun, 1; Jul, 1; Aug, 3; Sep, 17; Oct, 12; Nov, 6; Dec, 9

What are the average (mean), mode, and the median of these numbers? How significant do you think these statistical figures are in this case?


Suppose we define summer as June, July and August; autumn as September, October, and November; winter as December, January, and February; and spring as March, April and May. Write a paragraph or two speculating about the reason(s) for the seasonal counts of dead birds. What kinds of explanations might there be for the monthly or seasonal variations? What kind of graph might be most effective to illustrate this phenomenon? Create and print the graph in Excel, or you may sketch the graph by hand. You will be graded on the quality, organization, and effectiveness of your arguments, your writing and your graphs-not on whether your answer is "correct".

Teaching Notes and Tips

Since the assignment in its present format is intended as a final exam question, with the students expected to spend perhaps 20-30 minutes on it, students are not expected to have done any research, and expectations about hypotheses they might develop are limited.


However, if this were to be given as a take-home assignment or a term paper, much more could be expected/required. For example, hypotheses about hurricane seasons, spring and fall wave heights and wind velocities, the seasonality of toxic substances in the ocean, the difference between shore birds and offshore birds, etc., might be investigated.

Assessment

References and Resources