Nature of Science Day 2: Nature of Science and Engineering NSE 3-6 MSTP Region 11 Teacher Center Today’s Trainers: Tamara Moore and Selcen Guzey

Nature of Science Goals 1. Share experiences implementing engineering lessons. 2. Develop an understanding of the central tenets of the nature of science. 3. Learn how to implement lessons that highlight tenets of the nature of science.

Engineering Lessons Put your poster up. In your handout, you have space to record your observations about others’ engineering activities. Take 10 minutes then we’ll come back to debrief.

Engineering vs. Science What is engineering? What is science? How are the similar/dissimilar?

Science is … Body of Knowledge ProcessWay of Knowing Facts Definitions Concepts Theories Laws Observing Measuring Inferring Predicting Classifying Hypothesizing Experimenting Analyzing Scientific knowledge is based on evidence Scientific knowledge can change over time Creativity and imagination play an important role in science Science refers to a system of acquiring knowledge. This system uses observation and experimentation to describe and explain natural phenomena.

Nature of Science For the following statements, think briefly about the comment and decide whether you agree or disagree. State the rationale for or defend your answer. There is a single scientific method agreed upon and used by those involved in science. Because science is based on evidence, it can be used to answer any question. Imagination and creativity play a significant role in the work of a scientist. Scientific laws and theories are open to debate and can be changed. Because science is based on fact, bias does not play a significant role in scientific activities.

Nature of Science: Observations Please observe setup in the front Write down your observations Share your observations with your neighbor

Nature of Science: Observation and Inference Observation: ◦ Our perception of an object or an event, using as many senses as possible. Inference: ◦ Reasonable explanation that we construct on the basis of our observations. Science as a Way of Knowing: ◦ Scientific knowledge is based on observation and inference

Nature of Science: Observation and Inference

Seven Blind Mice

Nature of Science: Tricky Tracks You are a group of paleontologists’ called in to examine a set of fossils. What do you observe? What can you infer from your observations?

Nature of Science: Tricky Tracks Individually make a “T-chart” on a blank piece of paper Title one column “Observations” and the other “Inferences” Separate our ideas into observations and inferences

Nature of Science: Tricky Tracks A new piece of the fossil evidence is discovered What do you observe? What can you infer?

Nature of Science: Tricky Tracks A third piece of the fossil record is discovered. Write down your story/explanation for what happened.

Teaching the Nature of Science The activity aims to help students: Distinguish between observation and inference. Realize that, based on the same set of evidence (observations, or data), several answers to the same question may be equally valid. Scientific knowledge is partly a product of human inference, imagination, and creativity, even though it is, at least partially, supported by empirical evidence. As such, scientific knowledge is never absolute or certain. This knowledge (including theories and laws) is tentative and subject to change.

Nature of Science: Observations

How can it be that some of us see only one face and not the other? Is it possible that some scientists may look at the same piece of evidence or set of data and see different things? The knowledge and expectations with which we approach any phenomenon may affect the way we interpret that phenomenon: Observations are theory- laden

Nature of Science: Fish is Fish

What Lionni’s story tell us about observation and inference? The role of creativity and imagination in science? What Lionni’s story tell us about how students learn? ◦ new understandings are constructed on a foundation of existing understandings and experiences. ◦ factual information is not enough – need to develop conceptual understanding

Nature of Science: The Role of Hypotheses What is a hypothesis? What is a law? What is a theory? How are they related?

Nature of Science: The Role of Hypotheses

Nature of Science: Black Box Activities Investigate the behavior of the black box. Record your observations in your notebook. What are the “laws of tube strings”? Develop a hypothesis to explain the observable behavior of the box. Test your hypothesis.

Nature of Science: Black Box Activities

Nature of Science: Another Black Box Activity Rule: You cannot open the box Investigate the behavior of the black box. ◦ What do you think is inside your black box? Record your observations in your notebook. Make inferences about what you think is inside your black box and draw a picture.

Nature of Science: Another Black Box Activity Meet with a group and discuss the diagram that you drew. ◦ Resolve any disagreements You will need to come up with one agreed upon diagram. Choose one person to draw you diagram on the whiteboard.

Nature of Science: Another Black Box Activity Now that you have seen the models, here are the four options – teacher info.

Nature of Science: Black Box Activities Black-box activities can be used to convey to students appropriate conceptions of many aspects of the NOS. Students can be helped to understand: The distinction between observation and inference. That scientific knowledge is partly a product of human inference, imagination, and creativity. That scientific knowledge is, eventually, empirically based (i.e., based on and/or derived from experiment and observation). That scientific knowledge (both theories and laws) is tentative and subject to change. That scientific models (e.g., atom, gene) are not copies of reality. Rather, these models are theoretical entities used to explain natural phenomena.

Should you let the students open the box? Reasons to not let them: ◦ More like science Reasons to let them: ◦ Blackbox activities where students build a prototype is a version of reverse engineering. Why might engineers do something like this?

Nature of Science: Black Box Activities In addition, these activities provide students with opportunities to practice some science process skills. Among these are: Observing and collecting data. Inferring, hypothesizing and devising `ways' to test those hypotheses (or inferences). Constructing models.

Connecting Process and Content

Reviewing the Role of Hypotheses

Behavior of Magnets and Magnetic Materials The purpose of this laboratory investigation is for you and your group to explore how magnets and magnetic objects behave. Record observations from Demo #1 What generalizing statement/law can we make? Like poles repel and opposite poles attract

Behavior of Magnets and Magnetic Materials What kinds of materials does a magnet affect? Record observations from Demo #2 What generalizing statement/law can we make? Materials that are attracted to a magnet are called ferromagnetic Iron and Nickel are ferromagnetic materials

Behavior of Magnets and Magnetic Materials How do you make a magnet? Testing “rubbed nails” Place one end of the bar magnet over one end (tip or head) of an unrubbed nail and rub in one direction only to the other end. Then lift the magnet away from the nail and repeat the process a few times, always rubbing in the same direction.

Behavior of Magnets and Magnetic Materials Are rubbed nails the same as magnets? Test behavior of rubbed nails Experiment # 1 Place a rubbed nail on the floater, making sure that other rubbed nails and the magnet are far away. Spin the floating rubbed nail gently, and watch it for at least half a minute until it seems to settle down. Repeat this two or three times.

Behavior of Magnets and Magnetic Materials Experiment #2 Systematically test interactions of rubbed and unrubbed nails.

Behavior of Magnets and Magnetic Materials Record your observations Tip of unrubbed nail Head of unrubbed nail Tip of rubbed nailHead of rubbed nail Tip of unrubbed nail brought near Head of unrubbed nail brought near Tip of rubbed nail brought near Head of rubbed nail brought near

Behavior of Magnets and Magnetic Materials Based on your observations in Experiments #1 and #2, indicate which of the following statements is supported by the evidence. A rubbed nail is a ferromagnetic material and behaves like a magnet. A rubbed nail is a ferromagnetic material but does not behave like a magnet. An unrubbed nail is a ferromagnetic material and behaves like a magnet. An unrubbed nail is a ferromagnetic material but does not behave like a magnet.

Behavior of Magnets and Magnetic Materials What are the different “kinds” of magnets that you can make from rubbing a nail? What are the different ways that you can make each of these “kinds” of magnets? Draw sketches in your notebook. N S

Behavior of Magnets and Magnetic Materials What are two different ways that you can rub your nail with a magnet so that the pointed end becomes the North Pole and the head end becomes the South Pole?

Behavior of Magnets and Magnetic Materials What are two different ways that you can rub your nail with a magnet so that the head end becomes the North Pole and the pointed end becomes the South Pole?

Behavior of Magnets and Magnetic Materials The purpose of this laboratory investigation is for your group to come up with a model that can help explain your observations. How can we explain our observations in terms of a model of magnetism? Draw pictures with a written explanation of your model SN Before rubbing After rubbing

Behavior of Magnets and Magnetic Materials

Your model should: Make sense to you Account for both the experimental observations you made previously Guide you in making predictions about what would happen in experiments that you had not yet done.

Behavior of Magnets and Magnetic Materials If predictions based on your model are confirmed by new experiments, you do not need to modify your model. However, if your new experimental observations differ from the predictions based on your model, then you need to modify your model. You continue this process until you have a model that can account for a wide range of phenomena.

Behavior of Magnets and Magnetic Materials Use your model to predict what might happen in a new situation Imagine that you rubbed your nail and then cut the nail in half. Sketch what your model predicts the inside of each of the two halves would look like

Behavior of Magnets and Magnetic Materials Based on your model, make the following predictions about what would happen if you were to bring the North Pole of a rubbed nail near each end of the two half nails. The model predicts that the North Pole of a rubbed nail will _____ the flat end of the head piece half nail. The model predicts that the North Pole of a rubbed nail will _____the cut end of the head piece half nail. The model predicts that the North Pole of a rubbed nail will _____the cut end of the point piece half nail. The model predicts that the North Pole of a rubbed nail will _____the pointed end of the point piece half nail.

Behavior of Magnets and Magnetic Materials Test your predictions. Prepare two rubbed nails so their pointed ends are North Poles. Ask your instructor to cut one rubbed nail in half. Place the head piece of the half nail on the floater. Bring the North Pole of the second rubbed nail near the two ends of the floating half nail. Record Observations Repeat with the pointed half nail. Record Observations

Behavior of Magnets and Magnetic Materials How did your observations compare with your predictions based on your original model? Do you need to modify your original model? Draw and share your revised model SN Before rubbing After rubbing

Behavior of Magnets and Magnetic Materials

Before rubbing After rubbing

Behavior of Magnets and Magnetic Materials Iron Filings Experiment Part I: Slide a rubbed nail’s pointed end to colored tip of the compass needle. What happens to the colored tip of the compass needle? Now turn the nail around and slide its’ head toward the colored tip. What happens to the colored tip of the compass needle? Now repeat this with unrubbed nail. Compare that behavior with the interaction of a compass with the rubbed nail.

Behavior of Magnets and Magnetic Materials Part II: Describe what happens to the compass needle when you slide the rounded end of the test tube filled with iron fillings toward colored tip of the compass. Turn the test tube around and slide its taped end toward the compass. Describe what happens to the compass needle. Is the test tube behaving like a magnet? Describe your evidence for your answer.

Behavior of Magnets and Magnetic Materials Part II Rub the test tube. Slide the end of the magnet along the test tube AND observe what happens to the iron filings. Slide the rubbed test tube toward the compass, and bring it toward the compass. Record how it interacts with the compass needle. Shake the test tube, and record how the test tube interacts with the compass again

Exit Slip What did you learn today about the nature of science (science as a way of knowing)? Which activities might work (with or without modifications) to teach about the nature of science in your classroom?