Hands-on Activity Basic Categorization Practice:
See, Touch and Discover

Quick Look

Grade Level: 1 (K-2)

Time Required: 30 minutes

Expendable Cost/Group: US $1.00

Group Size: 2

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

NGSS Three Dimensional Triangle

A young boy touching a tree while blindfolded.
Students rely on their sense of touch to identify objects around them
Copyright © Flickr https://c1.staticflickr.com/9/8340/8204296725_c1dc8edb0b_b.jpg


Student teams identify and categorize various objects using their senses of touch and sight. One student chooses five objects for his/her blindfolded partner to describe and identify based solely on touch. Then they switch. Both students record their observations, describing the objects as: human-made or natural, living or non-living, as well as any other physical/sensory characteristics. Students become familiar with different classification systems and sharpen their vocabulary to describe the physical characteristics of different objects. They learn why engineers have a need to categorize materials.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Materials scientists and engineers use a complex system of categorization and naming based on the properties of materials. Physical properties can be seen, while chemical properties are more difficult to understand. Knowing the properties and characteristics of materials helps engineers understand and choose suitable materials for products and projects.

Learning Objectives

  • Build observation skills by using tactile perception to describe and distinguish objects.
  • How to categorize and sort objects in a logical fashion.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

2-PS1-1. Plan and conduct an investigation to describe and classify different kinds of materials by their observable properties. (Grade 2)

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This activity focuses on the following Three Dimensional Learning aspects of NGSS:
Science & Engineering Practices Disciplinary Core Ideas Crosscutting Concepts
Plan and conduct an investigation collaboratively to produce data to serve as the basis for evidence to answer a question.

Alignment agreement:

Different kinds of matter exist and many of them can be either solid or liquid, depending on temperature. Matter can be described and classified by its observable properties.

Alignment agreement:

Patterns in the natural and human designed world can be observed.

Alignment agreement:

  • Compare the natural world and human-made world. (Grades Pre-K - 2) More Details

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  • Explain that materials are selected for use because they possess desirable properties and characteristics. (Grades Pre-K - 2) More Details

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  • Describe the properties of different materials. (Grades 3 - 5) More Details

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  • Identify and describe characteristics of natural materials (e.g., wood, cotton, fur, wool) and human-made materials (e.g., plastic, Styrofoam). (Grades Pre-K - 2) More Details

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  • Identify and explain some possible uses for natural materials (e.g., wood, cotton, fur, wool) and human-made materials (e.g., plastic, Styrofoam). (Grades Pre-K - 2) More Details

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  • Differentiate between living and nonliving things. Group both living and nonliving things according to the characteristics that they share. (Grades Pre-K - 2) More Details

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  • Recognize that people and other animals interact with the environment through their senses of sight, hearing, touch, smell, and taste. (Grades Pre-K - 2) More Details

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  • Sort objects by observable properties such as size, shape, color, weight, and texture. (Grades Pre-K - 2) More Details

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Materials List

  • blindfolds, enough for half the class; alternatively: use small lidded containers such as ice cream containers, tissue boxes or shoe boxes so that students can put their hands inside to feel the objects without seeing them
  • a selection of objects, enough quantity and variety so student teams have their own sets of objects so that each partner identifies different objects. Example objects: rocks, pinecones, leaves, seashells, wood, plastics, pens, pencils, paper, Styrofoam, fabric, leather, wool, cotton, corks, sponges (sea and artificial), fruits, vegetables.
  • Touch and Discover Worksheet

Worksheets and Attachments

Visit [www.teachengineering.org/activities/view/touch_and_discover] to print or download.


How would you describe a tomato? (Listen to student suggestions.) Well, if you are looking at the tomato, the physical characteristics can be described as red and round. But, what if you could not see the tomato and could only describe it by touch? (Listen to student suggestions.) Then you could describe it as smooth and hard or soft, depending on how ripe it is. Would you be able to guess the object was a tomato if you held it in your hands while blindfolded? (Maybe smelling it would help!)

How else could you describe a tomato? Is it a natural-made or human-made object? What is a tomato used for? There are many ways to classify objects and put them into groups. With today's activity, you will sharpen your observation and descriptive skills.



Objects have certain characteristics that permit them to be grouped with similar objects, and that grouping can help us understand and use these objects.

Review the definition of characteristics. Provide examples, such as living, non-living, natural, human-made, etc.

Review how objects can be grouped, such as by size, color, shape, weight, use, texture. For example: all these objects are brown or all these objects can be eaten or all these objects can roll.

Review examples of descriptive words (a good way to tie English and language skills into the sciences) that express observations made by the senses (sight, touch, smell, hearing, taste).

Before the Activity

  • Gather materials and make copies of the Touch and Discover Worksheet.
  • Put all the objects in a box or on a table out of view of the students.
  • Prepare enough blindfolds (or small containers) for each group.
  • Discuss with the children different methods for grouping objects.
  • Discuss the difference between natural and human-made, and living and non-living.

With the Students

Divide the class into pairs (or small groups) of students, and hand out the blindfolds.

Begin the Activity:

  1. Blindfold partner A. Have partner B go to the table and choose five objects.
  2. Without letting partner A see what was chosen, categorize the objects using the worksheet.
  3. Have partner A hold each object one at a time, examining it thoroughly with his/her hands. Then have partner A describe the object to partner B.
  4. Partner B records the data on the worksheet.
  5. After all five objects are described by partner A, repeat the activity, this time let partner B be blindfolded, and partner A choose the objects to be identified.
  6. Once both partners have had a chance to identify objects using only touch, explore how the 10 objects identified can be grouped. Think about how they are related or similar to each other, and their different uses.
  7. Conclude with a class discussion, as described in the Assessment section.
  8. See the Activity Extensions and Activity Scaling sections for ideas on how to continue the activity further.


categorize: To arrange or describe by labeling or giving a name to a group of things that have some quality or qualilties in common.

characteristic: A distinguishing feature or quality.


Concluding Class Discussion: Lead a class discussion to review results and compare experiences. Ask students the following questions. The basic idea is that objects have certain characteristics that allow them to be grouped as similar objects, and that grouping can help you to understand and use these objects.

  • How did each group categorize the different objects?
  • Is there only one right way to group the objects?
  • Which ways are better? What are the best characteristics to use when grouping objects?
  • How easy (or hard) was it to identify and describe objects using only touch? Why?
  • Why is it good to practice using different observation skills?

Investigating Questions

  • How can different objects be categorized and described using only your sense of touch?
  • Why is it important to be able to categorize different objects?
  • How do engineers use information like this to help them?

Safety Issues

  • Make sure not to include any objects that may be sharp or dangerous.

Activity Extensions

Extend the activity by asking students to each bring five objects from home. As a class, group and re-group them according to common characteristics.

Combine this activity with a lesson on animal classification.

Have students each describe an object to the class. This helps students develop language and descriptive skills and as well as listening and visualization skills.

Continue as a matching game, in which each blindfolded child matches what s/he feels with an object from a group of objects that s/he can see.

Activity Scaling

This activity can be easily modified to be suitable for different age groups. And, as students become more experienced, you can make it more challenging.

  • For younger students, expect them to sort according to shape and color. Provide simple, easily distinguishable objects.
  • For more advanced students, expect them to sort according to uses and material. Provide more variation in the objects.
  • As students develop their skills, challenge them to use more descriptive words and more sophisticated methods of sorting.
  • Make it more challenging by requiring that students brainstorm uses for the objects and materials, instead of just physical characteristics classification.
  • For more advanced students, have students pick out five objects that they grouped in a certain way and have their partners identify the objects and the logic for the grouping.


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Gutierrez, Charles. The Touch n Feel Box Lesson. Academy Curricular Exchange Columbia Education Center Science. Accessed October 24, 2011.http://ofcn.org/cyber.serv/academy/ace/sci/cecsci/cecsci153.html


© 2013 by Regents of the University of Colorado; original © 2004 Worcester Polytechnic Institute

Supporting Program

Center for Engineering Educational Outreach, Tufts University

Last modified: February 17, 2018

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