Middle School Highlight Objective 1-4

1. Middle SchoolHighlight Objective 1-4 Students should be able to make inferences, to recognize meaningful data, to use evidence and data to evaluate the strengths and weaknesses of scientific explanations and to analyze possible unexpected results from an investigation.

2. Inference • An explanation for an event based on past experiences. EXAMPLE: You walk outside and notice puddles in the street and the grass and shrubs are wet. WHAT CAN YOU INFER? Based on past observations, you might infer that it rained last night. Although you did not actually see it raining, past observations have allowed you to infer why the puddles and wet lawn were present. ARE THERE OTHER POSSIBLE INFERENCES? EXPLAIN

3. Observations – information about an object or event made using one or all of your senses Example: A witness may actually observe a crime being committed Inferences - conclusions based upon an observation that you or someone else has made Example: A police officer may visit a crime scene and from his observations infer what happened. Inferences are NOT Observations

4. Inferences-Another Definition • Another definition of an inference is to conclude something from certain evidence • Is an inference the same thing as a scientific conclusion?

5. Answer: No – Why? • In science, results from a single experiment are not sufficient to make a conclusion. • However, a scientist can make inferences from a single experiment. • Inferences can also be made about events that have yet to occur. When we predict trends we are inferring what we think will happen.

6. Predicting Trends-Example • On 12/1 sunset occurred at 5:20 p.m. • On 12/2 sunset occurred at 5:21 p.m. • On 12/3 sunset occurred at 5:22 p.m. • On 12/4 sunset occurred at 5:23 p.m. • What inference can you make regarding the time of sunset on 12/5? • Answer: Sunset will occur later than 5:23 p.m. (There are also other inferences. Can you think of one?)

7. Unexpected Data • Using the observations on the previous slide, you might predict that sunset would continue to occur earlier and earlier each day. However, we know that this is only true until mid-December. At this point, days start to become longer and sunset starts becoming later. Sometimes unexpected data may lead to new inferences.

8. EXAMPLE A scientist drops 3 objects of different masses from the same height. He notices that the heaviest objects hit the ground first. Next he drops two objects of the same mass and he notices that they both hit the ground at the same time. What is one possible inference?

9. Maybe the mass of an object affects the time it takes to fall. Perhaps air resistance affects the fall time of different objects. Gravity could be affecting the time it takes an object to fall. HOW CAN A SCIENTIST PROVE WHICH INFERENCE IS CORRECT? Test the inference by doing a controlled experiment Falling Object Inference

10. EXAMPLE • An individual notices that when white light is passed through a prism it emits a rainbow of colors. • What are some possible inferences you can come up with to explain why this occurs?

11. Prism Inference • Perhaps the prism changes the original properties of white light. • Perhaps the prism magnifies the white light. • Maybe the prism separates the white light into its individual components. • HOW CAN A SCIENTIST PROVE WHICH INFERENCE IS CORRECT? • Test the inference by doing a controlled experiment

12. Inferences • By the way, if you chose an inference that wasn’t listed on either of the previous slides it doesn’t mean your inference is wrong. • That’s the good thing about inferences, until they are proven correct, through controlled experiments, no one is ever sure if they are right or wrong. • On the other hand, in science, you should always evaluate everything about a situation before you develop an inference.

13. EXAMPLE What really happened? Inferences that eventually led to conclusions… • Isaac Newton (1667) White light is made of all the colors of the rainbow. A prism bends the light so the colors become visible. • Galileo Galilei (1604) All objects fall at the same rate. (9.8 m/s2) http://galileo.rice.edu/por/galileo.html http://en.wikipedia.org/wiki/Isaac_Newton

14. EXAMPLE B A company has created a new chemical that is said to improve memory. 200 mice were divided into 2 groups. Both groups contain 100 males and 100 females. Group A will be injected with the chemical. Group B will be injected with the same volume of water. After 10 minutes, both groups will be run through a complex maze. This will done for 14 consecutive days to test for memory improvement. A • Evaluate the results: Did the chemical work? Could this become a conclusion? • Was there any data that was unexpected? If so, which group and which day?

15. Evaluate the results: Did the experiment work? Could this become a conclusion? Based on this one experiment you could infer that the chemical was increasing the speed of the mice thus their memory was improving. It could become a conclusion if it was repeated many times with the same results. Was there any data that was unexpected? If so, which group and which day? Yes, Group A on day eight. Group B had a slight aberration on Day 4.

16. EXAMPLE Study the graph to the left. Evaluate the strength & weaknesses of the following scientific explanation: The further a planet is from the sun the larger its average orbital speed is.

17. Strength: The statement recognizes a relationship between a planet’s distance from the sun and its average orbital speed.Weakness: The explanation misinterpreted the data. The correct interpretation is: The further a planet is from the sun the smaller its average orbital speed is. Evaluate the strength & weaknesses of the following scientific explanation: The further a planet is from the sun the larger its average orbital speed is.

18. YOUR TURN • On a piece of paper – number 1 to 6 • The next slides will each present you with charts, pictures or information • Study this information • Select the inference that best fits with the information

19. Balance 1 1 proton 1 neutron #1. 1 proton 1836 electrons Balance 2 Study the 2 atomic balances shown above. Which of the following inferences, is correct? A. 1 neutron probably has the same mass as 1 electron B. 1836 neutrons probably have the same mass as 1 electron • 1836 electrons probably have the same mass as 1 neutron • Electrons have more mass than either protons or neutrons

20. Balance 1 1 proton 1 neutron #1. 1 proton 1836 electrons Balance 2 Study the 2 atomic balances shown above. Which of the following inferences, is correct? • 1836 electrons probably have the same mass as 1 neutron (Correct Answer) Why is this the best inference? Since 1 proton and 1 neutron have the same mass and 1 proton has the same mass as 1836 electrons you can infer that it would take 1836 electrons to have the same mass as 1 neutron

21. + #2. Proton, positive charge + + Neutron, no charge + Electron, negative charge • Study the two illustrations shown above. Which of the following inferences, is correct? • The atom pictured above probably has an overall charge of +1 • The atom pictured above probably has an overall charge of 0 • The atom pictured above probably has an overall charge of -1 • There is not enough information given to make an inference regarding the charge of the pictured atom.

22. + #2. Proton, positive charge + + Neutron, no charge + Electron, negative charge • Study the two illustrations shown above. Which of the following inferences, is correct? • B.The atom pictured above probably has an overall charge of 0 (Correct Answer) • By using the key to the left you can infer which particles are protons, electrons, and neutrons. You can count that this atom has 3 electron (- charges) & 3 protons (+charges). These charges cancel one another out. Because neutrons have no charge, the overall charge is 0.

23. #3. On Earth, Johanna weighs 100 lbs. She calculated what her weight would be at several other locations in the solar system The results are shown in the table. -> Which of the following statements is best supported by the information in the table? A.Venus has more gravitational force than Earth B. Mars has less gravitational force than the Moon. C. Earth has four times the gravitational force of Mars. D. Jupiter has more than twice the gravitational force of Earth http://www.doe.mass.edu/mcas/2005/release/g8sci.pdf

24. #3. On Earth, Johanna weighs 100 lbs. She calculated what her weight would be at several other locations in the solar system The results are shown in the table. -> • Which of the following statements is best • supported by the information in the table? • Jupiter has more than twice the gravitational force of Earth (Correct Answer) • Weight is simply a measure of the gravitational pull on an object. Johanna’s weight on Jupiter is more than 2x her weight on earth. http://www.doe.mass.edu/mcas/2005/release/g8sci.pdf

25. #4. 50N 20N The diagram to the left illustrates a lab activity performed by a student. The end result of the activity was that the cylinder moved to the right with 30 N of force Using the activity from above, what can you infer would happen to the cylinder if everything stayed the same except the 20N of force was replaced with 50 N of force? • A. The cylinder would not move because the net force would be zero. • B. The cylinder would move left with 50 N of force. • C. The cylinder would move right with 50 N of force. • D. The cylinder would move left with 100 N of force.

26. #4. 50N 20N The diagram to the left illustrates a lab activity performed by a student. The end result of the activity was that the cylinder moved to the right with 30 N of force Using the activity from above, what can you infer would happen to the cylinder if everything stayed the same except the 20N of force was replaced with 50 N of force? • A. The cylinder would not move because the net force would be zero. (Correct Answer) • If the two forces were equal & opposite then you can infer that the object should stay at rest. (No movement)

27. #5. Study the table, shown to the left. Which of the following inferences, is correct? Speed of Sound Through Different Media • Sound moves faster through water as compared to nickel and • copper • B.Sound moves faster through copper as compared to wood and • silver • C.Sound moves slower through silver as compared to copper • and nickel. • D.Sound moves slower through water as compared to copper • and silver.

28. #5. Study the table, shown to the left. Which of the following inferences, is correct? Speed of Sound Through Different Media D.Sound moves slower through water as compared to copper and silver. (Correct Answer) Although the chart shows how fast sound is moving through a substance you can also infer which substance it is moving slowest through.

29. #6. http://imagers.gsfc.nasa.gov/ems/visible.html When objects move away from Earth the wavelengths of light are stretched. The object thus emits a red shift of light. • Study the diagram above. An astronomer • on planet Earth, studying a far away galaxy • notices it emits a blue shift of light. Which • of the following inferences is most likely • correct? • A. The galaxy has little energy. • B. The galaxy is moving toward the Earth. • The galaxy is moving away from the Earth • The galaxy is stationary.

30. #6. http://imagers.gsfc.nasa.gov/ems/visible.html When objects move away from Earth the wavelengths of light are stretched. The object thus emits a red shift of light. Study the diagram above. An astronomer on planet Earth, studying a far away galaxy notices it emits a blue shift of light. Which of the following inferences is most likely correct? B. The galaxy is moving toward the Earth (Correct Answer) Since objects moving away emit a red shift of light it can be inferred that colors at the opposite end of the spectrum would be moving closer.

31. Summarize-Think, Pair, Share • Fold a piece of paper lengthwise. • On the left side list any information that describes what an inference is. • On the right side list any information that describes what an inference is NOT. • When you are finished, find a partner to discuss the information you and he/she have written down.