Akron Global Polymer Academy Lesson Plans

Observations and Inferences

Grades: 5-8
Author: Sandy Van Natta
Source: The original source is unknown

Abstract

Students will learn to distinguish observations from inferences. Students observe what they think is a burning candle and list all their observations. In reality they are observing a cylinder of apple or potato with a burning nut on the end. When all the students' observations are listed, a discussion is lead to separate actual observations from inferences students have made. Next students observe the appearance and behavior of two balls which are similar in appearance but very different in composition. Observations and inferences are made relating to the two balls.

Objectives

What should students know as a result of this lesson?

• Students should be able to evaluate a list of statements and divide them into two categories - observations and inferences.

What should the students be able to do as a result of this lesson?

• Students should be able list observations relating to a simple activity
• Students will be able to identify a statement as an inference based on the observations

Materials

Engagement Activity

• Apple or potato
• Large diameter clean cork borer or 1 to 2 cm diameter rigid plastic tube
• Nut (Brazil, almond, walnut)
• Paring knife
• Matches
• Lemon juice or Fruit Fresh

Getting Ready:

• Making the Candle: Push the cork borer or plastic tubing through the largest portion of the apple (or potato) flesh to make the cylinder shaped "candle" body. Dip the apple cylinder in lemon juice or Fruit Fresh to avoid discoloration. Cut several 2.5 cm slivers from a nut to make the wicks. Push a sliver into the top of the apple cylinder. Light the sliver only long enough to char the "wick". Making an extra backup candle is a good idea.
• Preparing for the Demonstration: Light a second wick to determine how long it will burn. This will give you an idea of how long you can allow your candle to burn during your demonstration.
• Practice what you are going to say in front of the class. Avoid using the word candle.

Elaboration Activity

• 1 set of Happy/Sad Balls (available from Educational Innovations #SS-3 at www.teachersource.com)
• 1 meter stick
• 1 balance

Assessment Activity

• A single frame of a cartoon cut from a comic strip

Procedures

Engagement

1. Discuss the importance of making observations in science.
2. Tell your students you are going to do an activity in front of the class and ask students to make as many observations as they can. (Avoid using the word candle.)
3. Ask for a student volunteer to record the students' observations for all to see the list.
4. Light the "candle" without comment and have the volunteer begin listing the observations.
5. Before the flame has a chance to burn out on its own, blow out the candle, allow a few seconds for the wick to cool, and eat the candle.

Assessment: The evaluation is informal in this stage. Listen to student observations and comments and try to encourage the quieter members of the class to contribute to the list of observations being compiled.

Exploration

Once you have eaten the "candle" divide the class into groups of 2 and ask each group to evaluate the class list based on the last "event" - eating the candle.

Assessment Monitor the groups' discussions. Ask them to decide if all statements listed were truly observations. Ask them if they made any assumptions not actually based upon their direct observations.

Explanation

Lead a class discussion on the differences between observations and inferences. Observations are made using the 5 senses. Although sight is the most utilized sense, touch, hearing, and smell are still important. Taste should not be used in the science laboratory. Tools can be used to extend the senses so that quantitative (measurements) observations can be made. (Note - all observations made in this activity are in the form of descriptions and are qualitative in nature.)

Make sure to discuss with students the role technology has played in the development of tools. For example, we have gone from the use of the naked eye, to magnifying glasses, to light microscopes, to electron microscopes for use in viewing small objects. Each advancement in technology allows us to make more detailed observations.

Assessment: Have students look at the list generated by the class on the board. Ask the students divide the statements into two groups - ones that are true observations and ones that are inferences. For example, actual observations would include statements such as the wick was black, it was burning, the flame was orange, etc. Inferences might include such statements as it's a candle, the candle was melting, and the candle was made of wax.

Ask students to write definitions in their own words for an observation and an inference and give an example of each.

Elaboration

Give the students a set of Happy/Sad Balls. Ask them to make a list of observations based on both the appearance of the balls and the behavior of the balls when bounced. Students should be given a meter stick to measure the height of the bounce of each ball and a balance can be used to mass the balls. After completing their list of observations, ask students to make inferences concerning the balls based upon their observations. Observations may include the color, size, mass, and texture of the balls. Inferences may relate to the composition or the density of the balls or whether the balls are solid or hollow.

Assessment: Have students complete the worksheet attached and evaluate the worksheet.

Prerequisites

N/A

Best Teaching Practices

• Discrepant Events
• Questioning
• Discussion
• Learning Cycle

Alignment with Standards

NGSS Standards:

• MS-PS1-1 Develop models to describe the atomic compostion of simple molecules and extended structures.
• MS-PS1-3 Gather and make sense of information to describe that synthetic materials come from natural resources and impact society.
• MS-PS2-2 Plan an investigation to provide evidence that the change in an object's motion depends on the sum of the forces on the object and the mass of the object.
• MS-PS3-1 Construct and interpret graphical displays of data to describe the relationships of kinetic energy to the mass of an object and to the speed of an object.

Common Core Standards:

• RST.6-8.1 Cite specific textual evidence to support analysis of science and technical texts.
• RST.6-8.3 Follow preciesly a multistep procedure when carrying our experiments, taking measurements, or performing technical tasks.
• WHST.6-8.2 Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.

National Standards:

• Content Standard A: 5-8 Science as Inquiry

Ohio Standards:

• Grades 6-8 Scientific Inquiry Benchmark A
• Grades 6-8 Scientific Inquiry Benchmark B
• Grades 6-8 Scientific Ways of Knowing Benchmark A

Content Knowledge

Observations are made using the senses. Descriptions are qualitative in nature. Tools are used to extend the senses. Information obtained using tools is often numerical in form and is therefore quantitative in nature. As technology has given us better and better tools, the number of observations upon which we can base our inferences has greatly increased. For example, we have progressed from looking at the stars with the naked eye, to using ground based telescopes, to space based telescopes. We use computers to store and sort the millions of observations that can be made daily. However, computers do not make the inferences - humans do!

Sometimes students make value judgments and think they are observations. A statement such as the ball is pretty is a judgment and not directly observed or measured.

The Happy and Sad balls used in this activity are made from the polymers (long chains of repeating units) neoprene and polynorbornene, respectively. Neoprene is elastic and used in products such as diving wet suits. Polynorbornene is a good shock absorber and used in tires or even as a lining in ballistic containers used by bomb squads.

Safety

No special safety precautions are needed

Applications

Students should learn not to make assumptions without the facts.

Observations are vital in forming accurate conclusions in scientific experimentation.

Assessment

Give students a single frame of a picture from a comic strip. Ask them to list all the observations they can make from looking at the picture. Next ask students to make inferences from their list of observations.

Other Considerations

Grouping Suggestions: Be aware of students' abilities and ethnic backgrounds when choosing groups. Try to place students of varied abilities and backgrounds in each group.

Pacing/Suggested Time: The Engagement activity should take about 20 minutes to complete. The Exploration may take up to 30 minutes to complete.

Printable PDF Worksheets

Worksheet