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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.

Material scientists and engineers use a complex system of categorization and naming based on 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. categorization human-made materials natural observation skills physical characteristics sensory sorting touch Build observation skills by using tactile perception to describe and distinguish objects. How to categorize and sort objects in a logical fashion. Blindfolds, enough for half the class (Alternative to blindfolds: Use small lidded containers such as ice cream containers, tissue boxes or shoe boxes; students 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 set of objects with each partner identifying 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 Activity Worksheet 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. To arrange or describe by labeling or giving a name to a group of things that have some quality or qualilties in common. A distinguishing feature or quality. Objects have certain characteristics that allow them to be grouped with similar objects, and that grouping can help you to 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). Gather materials and make copies of the Touch and Discover Activity 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. Divide the class into pairs (or small groups) of students, and hand out the blindfolds. Begin the Activity: Blindfold partner A. Have partner B go to the table and choose five objects. Without letting partner A see what was chosen, categorize the objects using the worksheet. 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. Partner B records the data on the worksheet. 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. 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. Conclude with a class discussion, as described in the Assessment section. See the Activity Extensions and Activity Scaling sections for ideas on how to continue the activity further. Touch and Discover Activity Worksheet (doc) Touch and Discover Activity Worksheet (pdf) Make sure not to include any objects that may be sharp or dangerous. 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? 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? 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 the student develop language and descriptive skills and helps the rest of the students with 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. 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. 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