Thursday, July 23, 2015

Engaging Students by Choosing What Science to Teach

[This is a guest post by my friend, Dr. Tom Hsu, Co-founder of Ergopedia. You can read more about Tom at the end of this post.]

A typical science book is close to 1,000 pages. Intimidating. Dense. Very few students are able learn all the material in a typical science curricula in one year. This is especially true considering we actually have only 36 weeks, and would still be true if we had twice that much time. That doesn’t mean we couldn’t teach it. Teachers are pretty good at working under impossible conditions; we can teach anything. The students just wouldn’t be able to learn it all. Which brings me to my title; if the goal is to engage students in learning, and have them learn, then what science should we teach? Within that 1,000-page body of scientific knowledge and skills, what is most appropriate for our students? What is learnable, teachable, important, and relevant? Out of the teachable and learnable subset, what fits into our standards and assessments?

You love science! I love science. We each find our specific area of science fascinating, and long ago learned its language and customs. To help our students learn we all need to take the difficult but necessary step of moving to the other side of the desk. We must stand in the shoes of someone who does not speak our language, does not know the meaning of endoplasmic reticulum or molarity or periodic force. Someone who does not care at all that the quadratic formula is beautiful. Then we need to go outside the school system altogether. What knowledge and skills will help our students succeed in fields other than research science? Many fewer than 1% of students ever become research scientists. Should our curriculum be driven, as it is, by the purpose of preparing research scientists?

I became successful because of public schools. I can still remember exactly when I decided I liked science. In the sixth grade my teacher did a science lesson on paper airplanes. She brought in a student from a local college to help and he showed me different ways to make a paper airplane fly. Then they both helped me learn to make it fly even farther. I was hooked; I wanted to build airplanes and eventually went to college to study aerospace engineering. I was hooked because:
  • The curriculum was made meaningful to me.
  • I had a positive, successful (carefully structured) hands-on experience 
  • I got to do the real stuff, building an airplane, without lots of theory. Later, I wanted to learn the theory!
At Eastman Kodak, where I once worked in engineering, we had an informal prize whenever one of us needed to use calculus in our jobs. We awarded it only once during the several years I was there. I challenge you to think about each topic in your curriculum as it applies to success in real life, outside of science. You will find that many ideas in “standard” curriculum are not useful! Maybe they were once useful, but no longer. Maybe they are useful to research scientists, but so what! We spend inordinate amounts of our precious class time teaching many concepts that are important to no one but specialists in our discipline. They are not bad concepts to teach. But what are we neglecting in their stead?

I believe the mission of k-12 science education is to give all graduates of high school useful scientific and technical knowledge and skills. By “useful”, I mean the things they can use in their lives, outside of laboratories and outside of science education. Leave the universities to train the research scientists. We need to prepare everyone else; the business people, the contractors, and most important the future parents, to understand how our technical world operates. People have a tendency to fear and mistrust what they don’t understand. America became great on the basis of our technical and scientific prowess. We need to keep that torch burning by making sure all Americans are able solve problems and make informed technical decisions based on sound scientific knowledge and reasoning.

Observation: Students are engaged when they are successful at learning. Therefore, curriculum should provide learnable, understandable content that is grade-appropriate.

The first high school science course many students take is biology. Open a typical high school biology book and look at the first few chapters. You will find protein synthesis, respiration reactions, DNA, enzymes, catalysts, hydrogen bonding, and a laundry list of fairly advanced chemistry topics! I have found the Kreb's Cycle, a graduate level topic not so long ago, in an introductory high school biology book in the introductory chapters. Is this how to engage students in science? By bombarding them with 2,000 new vocabulary words and concepts they are unprepared to understand? In fact, the traditional high school biology course with its overemphasis on vocabulary and memorization disengages students from science.

There is a strong movement to put physics first in the high school curriculum followed by chemistry, then biology. Being a physicist, naturally I think of physics as the most important science, right? Wrong. The drastic changes in human society that came with the agricultural revolution (2,000 years) the industrial revolution (300 years) and the information revolution (40 years) will pale before the changes that will come as we explore our ability to change our very species itself and the detailed workings of our planet. If the wrong microbe were to get loose homo sapiens could become extinct far faster than the dinosaurs.

I agree with the physics first initiative because physics is the easiest way to engage students in learning systems thinking and quantitative reasoning. Traditional biology with its overemphasis on memorization and vocabulary fails to adequately prepare students to understand their role in the larger ecosystem of Earth or even the functions of their own bodies. To understand modern biology you really need a foundation of chemistry. And to understand why chemistry occurs you need to understand energy, atoms, and systems. That is why physics should be first: because it is the most direct way to teach the big ideas of energy, atoms, causality, and systems. Physics provides the foundation for chemistry, which is the foundation for biology.

Few students think physics is engaging because they don't like math. It has nothing to do with physics and virtually everything to do with how math is taught. Throwing the traditional wall of "physics" math at eighth and ninth graders will NOT get us where we need to be! Physics First needs to be a different physics than was Physics Last (or no physics). A ninth grade physics course must develop the big ideas of systems, energy, and atoms conceptually and mathematically, with the concept preceding the math and not vice versa. Energy conservation is such an important idea that it should not wait until mid-year. Many traditionally important results, such as free fall, and mechanical advantage can be developed using energy arguments far easier than with traditional vector algebra. We need to rethink how we teach physics as well as what we teach to develop a sound foundation of both understanding and quantitative thinking.

Observation: Questions are more interesting and engaging than facts.

I am a strong believer in guided inquiry. In guided inquiry a group of students is presented with a phenomena, offered some pertinent questions and a suggested path of inquiry that might lead to an explanation. We developed some very special experiments that create situations that are easy to describe and reproduce, yet deep in understanding. For example, imagine a track that starts with a downhill slope followed by a level section about as long as the slope. A little car starts from the top of the hill, rolls down the hill, along the flat, and then bounces off a rubber band at the bottom. After bouncing, the car then rolls backward and partially up the hill again. Students notice that the car never rolls back as high as it started. Why? What is the explanation for why the car never goes higher than it started? Energy of height (potential energy) is proportional to height. Energy of speed (kinetic energy) is proportional to speed. The car never rolls back higher than it started because that would require more energy than is available.

Once students see the big idea that the car needs more energy to get higher, we pose the next question: is there any way the car can be made to go higher than it starts? If so, how, and why? Once they are thinking in terms of limited energy, students quickly realize that they need to give the car more energy. For example, a small push downwards at the start gives the car additional energy. Pushing adds energy and the car can now roll higher than it started. By using a real car and track, students learn almost immediately about efficiency. Friction diverts some energy and it takes a substantial push just to get the car back to its initial height.

Curriculum and equipment must work together. You wouldn’t want your surgeon operating with a kitchen paring knife would you? A scalpel is specifically designed for surgery and the equipment for learning science should be created specifically to learn and not merely to demonstrate! Just as a scalpel is more than “a sharp knife” the effectiveness of a real car and track as a learning tool is based on designing the actual car and track to have just the right kind of friction, the right sorts of angles, the right kind of wheels and bearings, a technique for applying a controlled force, a way to measure level, and countless other details. You just can’t get this kind of deep learning to happen with sticks and strings. Actually you could, but few of us have Galileo’s talent, patience, or time!

Choosing what to teach

I believe we cannot teach all of the content in most science standards in a way that most of our students will learn it and retain it. That means we must choose which content to teach and which to ignore. We favor the use of some very practical questions when choosing what to emphasize in a curriculum.

Question #1: Is there a useful application of this concept, outside of academic science, that students can understand at the level they are at? If there is no such an application, or the application is incomprehensibly advanced, you should think very hard about teaching a different concept instead. There is plenty in the curriculum to choose from!

Electricity provides a good example of how to apply question #1. To most of the world, the important aspects of electricity are voltage and current. Voltage and current are the things we use every day when we plug in appliances or turn on a light. Current is what flows and does work. Voltage measures the available power that is carried by a quantity of flowing current, such as one amp. One amp of current from a 120 volt wall outlet carries 120 watts of power to do useful things. 120 watts can propel a bicycle and rider up a moderate hill. The same one amp of current flowing out of a 1.5 volt battery carries only 1.5 watts of power. 1.5 watts is barely enough power to light a night light; not nearly enough to ride up a hill. The amoount of current is the same. The voltage tells you how much power each amp carries. Voltage and current are real, measurable, every-day concepts students can measure and use. We build circuits, make light bulbs glow and only then, once the student has some successful experience and, only then do we ask what is really going on inside those wires. Then is the time to learn the more abstract concepts of electric forces and fields. We call this the STEM approach. We use practical applications of engineering and technology (amps and volts) to teach the science of physics (electricity and magnetism).


Consider the fact that virtually every traditional physics course begins the same topic of electricity with electric charges, the electric field, and Coulomb’s inverse square law of the force between two electric charges. Almost no one outside physics uses Coulomb’s law or cares that electrons really move from negative to positive. In many books the short (and inadequate) section on voltage and current is at the very end of the unit. Many (if not most) physics teachers never get to the end of the unit and therefore the majority of students never learn the practical application of electricity. Why do physics courses start with the abstractions of charges and electric fields? We call this the "anti-STEM" approach! The anti-STEM approach is to subtract all practical engineering and technology from the teaching of "pure science.


Question #2: Does the concept help build understanding of the big picture or is it a small detail?


I have seen a k-12 science curriculum that teaches density for two weeks, every year, in every grade, from grade 4 to grade 9. In the grand scheme of things density is a tiny detail. Its emphasis in the curriculum is far in excess of its importance. Physics is no better at prioritizing content. Fully one quarter of a traditional physics book is devoted to building up the equations of accelerated motion. There are subscripts, superscripts and symbols; there are diagrams and frictionless examples; and there are difficult-to-parse word problems that carefully construct situations of constant acceleration. Do you know that in the real world there are virtually no situations of constant acceleration! Students must survive a half-dozen chapters before they get to the really important and useful ideas of energy and systems.


Question #3: Is the concept important today, or is it only historically important?


Unless the historical development is really important to understanding what is useful today, we skipped it. We want students to learn science that they can use today, not science that was interesting 100 years ago. History is important, but not as important as having a scientifically literate population who can evaluate scientific issues rationally.


Question #4: How can you teach this concept while introducing the fewest number of new words or equations required for the student to learn and apply the concept?


This is hard for us since we know the language and customs of our scientific disciplines. Try marking out every word not in common use and see if you can still teach the big idea. The average educated person’s vocabulary is around 20,000 words. The average 9th grade biology book has more than 2,000 new words; words that a student must decipher to be able to understand the important ideas in the book; words that will never be used again outside the narrow world of research biology and medicine. Can we teach the ideas without this incredible barrier of words? For example, I have seen the term “endoplasmic reticulum” on an 8th grade state assessment. Why is this term there? In my humble opinion you can teach the important ideas in biology, such as ecosystems, food chains, anatomy and physiology, heredity, evolution, and the organization of life on Earth, without 90% of the big words. Wouldn’t you rather have students understand the important ideas instead of the specialized vocabulary?


Question #5: Is there a way for students to get hands-on experience with this concept?


Teaching the mathematical representation of electric fields (Coulomb's law) to ninth grade students is almost a waste of time. Students have neither the mathematical skills, nor the experiential background to understand and use the concepts. Unless you are willing to invest the time in providing experiences to give kids a handle on the abstractions, don't hold students responsible for learning material that can only be understood using mathematics above your students heads. That doesn't mean your shouldn't talk about cool things like time travel or quarks! It just means that "engagement topics" such as relativity should not be on the test, and students should know that they are not responsible for understanding time travel.

Using technology

Technology is a great way to introduce concepts in science and make them engaging by being relevant. For example, instead of starting a sound unit with the theory of waves, why not start by asking how a CD works? 100 years ago you could only hear music if you were next to a musician! Very few people heard enough musicians to even have a favorite band. The recording of sound was tremendously important to the development of culture, and engages kids. Exactly how do you capture a sound and record it so it can be played back? You probably can’t find a kid today who does not know what an MP3 file is. Do you know what an MP3 file is? How is it different from the sound recorded on a CD? The technique of starting with technology is interesting and engaging to students, I have done it many times. The other way (theory first) is boring to most students; I have done that too!

About the author

I should warn the reader that while I am expressing one personal opinion many of these ideas have come from other teachers across America. It has been my pleasure to have taught, and worked with, more than 18,000 teachers over the past 25 years, both in workshops across the country and in courses I have taught. Over time, I developed some of these rules from my own classroom teaching, in urban and suburban schools, public and private, with students ranging from fourth grade through graduate school.

Some of my critique of "pure science" comes from a background of practical engineering. Even in my "research" career I liked to build things, first at the superconducting accelerator at Stony Brook, and later on the Alcator tokamak fusion experiment at MIT. My work in industry including developing the first color copiers (Xerox, Dupont), manufacturing photographic paper and film (Kodak), manufacturing science equipment and publishing books (first with CPO Science and now with Ergopedia).

At heart, I am a teacher. When people ask me what I do, I proudly inform them that I am a science teacher. When asked how I got that way, I said that my own teachers made a huge difference in my life. My father was a cook and my mother was a waitress. I grew up in public schools, and along the way have been a carpenter, a cook, an engineer, a bicycle mechanic, a nanny, and even a musician (although, to be honest, I never actually earned any money as a musician). Every one of these experiences has enriched my ability as a teacher.

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