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Venn Diagrams
Venn diagrams have two (or more) overlapping circles, and students use these charts to compare and contrast topics. Students write and draw the differences in the parts of the circles that do not overlap and write and draw the similarities in the overlapping section. Sometimes teachers draw large Venn diagrams on chart paper and have the class work together to add the similarities and differences; otherwise, students work individually or in small groups to make Venn diagrams on construction paper. To save the time involved in carefully drawing and overlapping the circles to make a Venn diagram, teachers often use pizza pans as patterns to draw Venn diagrams on sheets of poster board and then laminate the sheets. Students use water-based pens designed for overhead projector transparencies to write on the laminated Venn diagrams, and they can be used over and over.
Venn diagrams are useful because they help students think more deeply and analytically about what they are reading and learning. For example, during a literature focus unit, students can compare and contrast two characters or compare the book and video versions of a book using a Venn diagram. The next picture shows a Venn diagram created by a second grader to compare two versions of The Town Mouse and Country Mouse, one written by Lorinda Cauley (1984) and the other by Jan Brett (1994). Making a Venn diagram may complete the activity, or making the diagram may serve as prewriting for a writing activity.
STEP BY STEP
The steps in making a Venn diagram are:
1. Discuss the similarities and differences between two topics with students. Some topics have more similarities, and others have more differences. Teachers think about the comparisons and contrasts ahead of time so that they can support students in their thinking. Teachers often ask questions to help students make the comparisons and contrasts. For example, when discussing The Town Mouse and the Country Mouse, the teacher of first and second graders asked these questions:
2. Draw a Venn diagram on a sheet of butcher paper, a sheet of poster board, or on sheets of construction paper and label the two circles with the names of the topics. Sometimes teachers add pictures along with the labels. Or teachers can make copies of the black-line master.
3. Have students write words and phrases and draw pictures representing the differences between the two topics in the outer parts of the two circles. Then have students write and draw about the similarities in the overlapping part of the circles.
4. Summarize the information presented on the Venn diagram, and support students in interpreting the information. The first and second graders who made the Venn diagram on the two versions of The Town Mouse and Country Mouse concluded that the two books were more alike than they were different.
5. Post the completed Venn diagram in the classroom and use the information on the chart for other activities. For example, students can use information prom the Venn diagram in writing a comparison-contrast essay or an opinion essay.
APPLICATIONS AND EXAMPLES
Venn diagrams can be used in a variety of ways in literature focus units and in thematic units. Some ways to use Venn diagrams in literature focus units are to compare and contrast: two characters the book and the video version of the book a book and its sequel two books with similar themes two books by the same author two authors or illustrators In thematic units, Venn diagrams are used to compare and contrast:
Even kindergarten students can use Venn diagrams. During a unit on pets in one kindergarten class, students signed their names on a Venn diagram to describe themselves as "dog lovers" or "cat lovers." Students who said they loved both kinds of pets signed their names in the overlapping circles.
Venn diagrams are used to both compare and contrast two topics; when teachers want to only con trast two topics, such as reptiles and amphibians, plant-eating and meat-eating dinosaurs, or the Arc tic and the Antarctic, T -charts are more effective than Venn diagrams. To make a T -chart, draw a large capital letter T and write the two topics above the horizontal stroke of the letter. An example of a T-chart contrasting reptiles and amphibians is shown below.
Brett, J. (1994). The town mouse and the country mouse. New York: Phi lomel. Cauley, L. B. (1984). The town mouse and the country mouse. New York: Putnam.