Classifying involves grouping things into definable categories based on like characteristics. Like comparing, it is something we do in our day-to-day lives. We classify the clothes we put into our closet. We classify the food we put on our kitchen shelves. Some of us classify the music CDs in our collection. Snowboarders provide a glimpse of the way they classify things when they talk about bad, rad, lame, sick, wack, and phat riding.

Certain rules govern these classifications: classical music CDs go together, Bob Dylan CDs have their own category, country goes with country. Even though we use rules to classify our CDs, snowboard riding, our clothes, and foods, most of us aren't expending much effort to decide if the canned tomatoes should go with the canned fruit or the canned vegetables. In the classroom, students can use a systematic process to classify important pieces of content knowledge. Students might classify organisms according to kingdom, phylum, class, order, family, genus, and species, or mathematical functions as linear, quadratic, trigonometric, exponential, or logarithmic.

Before reading “Recommendations for Classroom Practice,” take some time to reflect on your current practices and beliefs about classifying by completing the Reflecting on My Current Beliefs and Practices—Classifying worksheet in Figure 2.1 (p. 22).

Figure 2.1. Reflecting on My Current Beliefs and Practices—Classifying

What is the purpose of asking students to classify?  What kinds of activities do I use to help students classify?  I can think of a time that I asked students to classify, and I was pleased with the results. Why did it go well?  I can think of a time that I asked students to classify, and I was not pleased with the results. Why did it not go well?  What questions do I have about using classifying in my classroom?

Recommendations for Classroom Practice

Classifying is a complex process that students will need to learn about and practice. In this module, we discuss several approaches to use in the classroom:

• give students a model for the process,
• use familiar content to teach students the steps in classifying,
• give students graphic organizers for classifying, and
• guide students as needed.

Give Students a Model

If we want students to move beyond classification schemes that are defined for them, such as the food groups or the animal kingdom, we need to give them opportunities to classify items using their own rules for category membership. We might ask them to classify historical battles, works of literature, or types of exercises. When we ask students to complete these types of assignments, we need to teach them explicit steps for classifying, as shown in Figure 2.2 (p. 23), and help them to understand the process as a systematic strategy with rules and expectations. This process involves the critical step of determining the rules that govern category membership.

Figure 2.2. Model for Classifying

Steps for Classifying Identify the items you want to classify. Select what seems to be an important item, describe its key attributes, and identify other items that have the same attributes. Create the category by specifying the attributes that the items must have for membership in the category. Select another item, describe its key attributes, and identify other items that have the same attributes. Create the second category by specifying the attributes that the items must have for membership in the category. Repeat the previous two steps until all items are classified and the specific attributes have been identified for membership in each category. If necessary, combine categories or split them into smaller categories and specify the attributes that determine membership in the category.

Steps for Classifying for Younger Students What do I want to classify? What things are alike that I can put into a group? How are these things alike? What other groups can I make? How are the things in each group alike? Does everything fit into a group now? Would it be better to split up any of the groups or put any groups together?

(Adapted from Dimensions of Learning, Marzano et al., 1997.)

How things are classified influences our perceptions and behavior. When rules for category membership change, we change the way we think about items. Imagine if we classified food items in a grocery store according to color. Purposefully grouping items into different categories can give us a different perspective on those items. When a green, square object is grouped with other square objects, we tend to notice it is square. When the green, square object is grouped with other green objects, we tend to notice it is green. In the classroom, using classifying can influence what students see and think about what they are learning.

Use Familiar Content

You can use everyday examples to help students understand the process of grouping items and describing the rules for membership in a category. When asked, any snowboarder can explain the difference between “wack” and “phat” moves on the slopes—moves that fit into each category share a certain set of characteristics. Students can begin to understand that classifying influences our thinking and behavior by considering some classification systems that we take for granted. How would our behavior change if books in a library were grouped by size? How does our thinking change if we group an elephant first with people and things in a circus, and then with other wild animals that live in Kenya? Thinking about what defines a particular group and why an item fits into the group helps students to learn more about the content they are studying.

Give Students Graphic Organizers

Graphic organizers are tools students can use as a visual guide to the classifying process. Two popular graphic organizers for classification are shown in Figures 2.3 (p. 25) and 2.4 (p. 26).

Figure 2.3. Classification Organizer

Figure 2.4. Classification Organizer—Art Materials, Techniques, and Processes

Categories
Art Materials	Art Techniques	Art Processes
Paint Clay Charcoal Pencil Wood	Overlapping Shading Varying Size Varying Color Collage Perspective Stippling Glaze	Adding in sculpture Subtracting in sculpture Casting jewelry Constructing jewelry Mixing color
Blackline master available, p. 354

Guide Students As Needed

When students are first learning to classify, you can provide the items and the categories for the classification so that the activity is structured and students' attention can be focused on why items belong in certain categories. A structured classification activity can be appropriate for students in many situations. For example, if you want students to learn the specific characteristics of each of the four major food groups, you might provide a list of foods and ask students to explain where each belongs and why. Students' performance on this type of activity is based on how accurately they place the items into the categories.

After students have had some practice completing structured classification activities, you can give them items to classify, but ask them to form the categories themselves. This type of activity often extends students' understanding of the content they are studying. For example, asking students to group foods into one of four food groups can tell you how well they know the given rules for membership in each category. However, asking students to disregard these four food groups and form their own helps them to delve into what they understand about the characteristics of various foods. This activity requires students to think in a different way and forces them to answer the question: How would I group these items and why?

Tools to Facilitate Classifying in the Classroom

To guide your students effectively, you need to be confident of your own understanding of how to use classifying. Figure 2.5, Checking My Understanding—Classifying (p. 27), gives you an opportunity to apply what you have learned in the previous discussion. If you find it difficult to reclassify the items and answer the accompanying questions, we suggest you reread “Recommendations for Classroom Practice.” The other planning and assessment tools that follow will help you guide your students in classifying activities in the classroom.

Figure 2.5. Checking My Understanding—Classifying

The table below lists items grouped into three categories of resources. Take a moment to study these categories and the items in each.
Categories
Natural Resources	Human Resources	Capital Resources
Land Forests Rivers Oceans Sunlight Coal Pastures Mineral deposits	Police officer Mail carrier Teacher Engineer Taxi driver Construction worker Accountant Telephone operator Salesperson	Bricks Hammer Bus 2″ × 4″ lumber Table saw Dump truck Dishwashing machine Jackhammer Computer
Now it's your turn. Reclassify these items using categories that you determine. Take a moment to examine the new categories. Then answer the following questions:  What steps did you follow to reclassify the items?  What do you see differently about the items now that you have reclassified them?  What are the benefits are of reclassifying items? Why might a teacher ask students to reclassify items?

Assessing the Impact on Students

Rubrics are one tool you can use to gauge students' progress. Sample rubrics for evaluating students' progress in using the classifying process are provided in Figure 2.6 (p. 28). These rubrics can be revised, when appropriate, for students to use as part of the self-assessment process to help them reflect on their work.

Figure 2.6. Rubrics for Classifying

Classifying Rubric	Classifying Rubric for Younger Students
4  The student organizes the items into meaningful categories and thoroughly describes the defining characteristics of each category. The student provides insightful conclusions about the classification.	4  The student puts the items into meaningful groups. The student tells the important characteristics for each group. The student makes conclusions.
3  The student organizes the items into meaningful categories and describes the defining characteristics of each category.	3  The student put the items into meaningful groups. The student tells the important characteristics for each group.
2  The student organizes the items into categories that are not very meaningful, but addresses some of the important characteristics of the items.	2  The student puts the items into groups that do not have a lot of meaning.
1  The student organizes the items into categories that do not make sense or are unimportant.	1  The student puts the items into groups that do not make sense.
0  Not enough information to make a judgment.	0  The student does not try to do the task.

Planning Classroom Activities and Assessing Myself

Answering a series of questions will help you discover how you might use the strategies for using classifying presented in this module. You can use the Planning for Classifying Worksheet, Figure 2.7 (p. 29), to guide your thinking when planning classifying activities for students.

Figure 2.7. Planning for Classifying Worksheet

What knowledge will students be learning?  Do I need to set aside time to teach students the process of classifying? How will I teach students the process?  Will I ask students to use a graphic organizer?  How much guidance will I provide students?  How will students explain their work and communicate their conclusions?  How will I monitor how well students are doing with classifying?  What will I do to help students who are not classifying effectively?

Rubrics help assess student learning. You can also use a tool to assess yourself—how effectively you are using classifying strategies. Use Figure 2.8 (p. 30) to evaluate your effectiveness in using classifying.

Figure 2.8. Assessing Myself—Classifying

Module Reflection

Review your responses to the questions in Figure 2.1, Reflecting on My Current Beliefs and Practices—Classifying worksheet (p. 22). How has this module affected your thinking about teaching and learning? Use the space provided to record your thoughts.

• Reading this information affirms some of what I already knew about classifying
• Now, I better understand some things about classifying
• I think I will change how I use classifying in my classroom