A Simple Problem in Classifying
Use the words in the following list to write a letter to your family back in Europe on your life in in the New England Colonies about 1750:
Figure A1. Commonly-spoken vocabulary in the New England Colonies prior to the Revolutionary War (c. 1750).
Adapted from Barry K.Beyer. 1987. Practical Strategies for the Teaching of Thinking. Allyn & Bacon.)
Identifying Characteristics of a Binary System of Classification
Look at the set of "creatures" shown below and observe their similarities and differences. In the left hand column of Table 1, list at least three more observable properties by which the creatures could be grouped into two subsets. Then, in the "Yes" column, write the names of the creatures that have the property that you have identified. In the "No" column, write the names of the creatures that lack the property. An example is provided. Be aware that a subset may contain one or more than one creature; it cannot contain all of them, however.
Figure A2. Creatures to be classified.
Observable Properties | Yes | No |
---|---|---|
Speckled body (example) | 1, 5, 6 | 2, 3, 4 |
. . . | . . . | . . . |
. . . | . . . | . . . |
. . . | . . . | . . . |
Notice, as in the example, that for each property, the subsets include all the objects
in the original set and that every object is assignable to one and only one of the
subsets. Check to be certain that your work in the preceding chart meets these two
very important criteria.
Compare your answers with those of a classmate.
How were they different?
Binary classification can also be used when you wish to group objects together that have more than one property in common.