Categorizing Ideas

Before students can successfully identify main ideas and details, they need to know how to categorize. The “bucket” (Sedita, 2001) is an effective visual aid and metaphor for teaching students to categorize. Using a real bucket, a basket, a recycling bin, or any container that helps students visually separate information, teachers can ask students to engage in this multisensory activity as a means of helping them learn to group ideas, objects, or concepts together based on a topic. 

Teachers introduce categorizing by labeling the bucket with a category (main idea) and asking students to identify contents for the bucket (details) that fit the category. It’s best to begin with something familiar. For example, the teacher might label the bucket beach toys, and students might fill it with a shovel, a castle mold, a kickboard, and a Frisbee. Anything that may or may not fit in the category is debated by the group and either included or discarded. For example, students might note that a kickboard is usually used in a pool and should be discarded, and a Frisbee can be used in many places other than the beach. Such discussions improve students’ critical thinking skills and help them understand that categorizing is not an exact science.

When students understand the concepts underlying categorizing, teachers can choose a more advanced category from students’ studies. If students are learning parts of speech in Language Arts, for example, teachers might label the bucket nouns and ask students to fill the bucket with examples that fit the category.

Figure 1. For example, if students are sorting parts of speech, first label the “bucket” with the topic “nouns”. Then, give students pieces of paper with different words so that they can carefully debate which words are nouns and which are not. Finally, students place those that are nouns in the bucket. 

Once students can provide appropriate components for a category, teachers can give students the contents of the bucket and ask them to provide the label. If students are learning about dependent clauses in English, for example, teachers can provide a number of clauses and ask them to come up with the category dependent clauses to label the bucket.

Teachers should begin with basic and concrete ideas to help students master the skills of categorizing information. They should also be sure to always include items, ideas, or details that would not fit in the “bucket” to give students the opportunity to discuss why something wouldn’t fit. This activity provides an opportunity for teachers to discuss and engage with students’ critical thinking.  

Sample Categorization Ideas:

• Objects and colors
• Odd and even numbers
• Feelings
• Wild animals vs. pets
• Regular and irregular polygons
• Dependent and independent clauses
• Thematic information from a novel (supports or doesn’t support a theme)
• Character from a story (fits or doesn’t fit a certain trait) 
• Chemistry elements (gasses, halogens, metals) 
• Historical events (part of an era or not) 

Once students are adept at categorizing, teachers can then provide the details and have students define the bucket label. For example, a teacher could show students examples of dependent and independent clauses and students would then create a label for each of these sentence types. This alteration can lead to a valuable discussion about choosing a label that is not too broad or narrow for the bucket’s components. 

Categorizing strategies helps develop students’ skills in identifying the main idea and supporting details, since the main idea is equivalent to the bucket label and the supporting details are equivalent to the bucket’s contents.