One teacher on our Facebook page asked, “Could you explain the scientific process? There seems to be tremendous difficulty for my 3rd graders to grasp it.”
So I went to Dr. William McComas, who holds the Parks Family Endowed Professorship in Science Education at the University of Arkansas. When it comes to the history and philosophy of science in science education, he literally wrote the book. At the heart of “doing science” are questions. Here is what Dr. McComas has to say about explaining and exploring the scientific process for younger students:
Perhaps one reason why some students think that the scientific process is hard to grasp is that they believe that scientific thinking is somehow different from other kinds of normal organized thinking. Scientists are not any smarter then other folks but they do have curiosity that inspires them enough to spend time and effort to ask questions about the world.
So, scientists start to ask questions that other folks might not have been so curious about. To answer these questions scientists make observations, do experiments and review the work of others printed in books. They also take notes about what they have discovered and try to put all the information together in a way that makes sense based on the evidence. There isn’t any special order to these tasks. Science use all of these tools to try to answer the question.
Some textbooks include a six or more step process called the scientific method, but scientists don’t all use this same step-by-step technique. Some scientists start to answer the question by going to the library, some start with observations, some start with experiments, some start with hypotheses to guide their thinking and some have a much more open-ended approach. The steps in the “scientific method” are all useful and used by most scientists at least some of the time, but the scientific process is really just the careful, organized way that scientists look for information to try to answer questions. The most important thing to know is that anyone can use the scientific process to solve problems as long as they look at all the evidence and make conclusions carefully when there is enough evidence to do so.
Core Nature of Science Ideas to Inform K-12 Science Teaching
The Tools and Products of Science
Science produces, demands and relies on empirical evidence
Knowledge production in science shares many common factors and shared habits of mind, norms, logical thinking and methods such as careful observation and data recording, truthfulness in reporting, etc. The shared aspects of scientific methodology include the following:
Experiments are not the only route to knowledge
Science uses both inductive reasoning and hypothetico-deductive testing
Scientists make observations and produce inferences
there is no single step-wise scientific method by which all science is done.
Laws and theories are related but distinct kinds of scientific knowledge. Hypotheses are special, but general kinds of scientific knowledge.
There are two types of scientific questions. Questions of the relationship type are “laws” and question of why such relationships exist are “theory type” question.
Science and the Human Aspects of Science
Science has a creative component
Observations, ideas and conclusions in science are not entirely objective. This subjective (sometimes called ‘‘theory-laden”) aspect of science plays both positive and negative roles in scientific investigation
Historical, cultural and social influences impact the practice and direction of science
Scientific Knowledge and its Limitations
Science and technology impact each other, but they are not the same
Scientific knowledge is tentative, durable and self-correcting. (This means that science cannot prove anything but scientific conclusions are valuable and long lasting because of the way in which they are developed; errors will be discovered and corrected as standard part of the scientific process)
Science and its methods cannot answer all questions. In other words, there are limits on the kinds of questions that can and should be asked within a scientific framework
McComas, W. F. (2008). Proposals for Core Nature of Science Content in Popular Books on the History and Philosophy of Science: Lessons for Science Education. In Lee, Y. J. & Tan, A. L. (Eds.) Science education at the nexus of theory and practice. Rotterdam: Sense Publishers.
About Dr. McComas:
William F. McComas, Ph.D. is the inaugural holder of the Parks Family Endowed Professorship in Science Education at the University of Arkansas following a career as a biology teacher in suburban Philadelphia and professor at the University of Southern California. He is involved in many areas of science education research and policy development. He has served on the boards of directors of the National Science Teachers Association, the International History, Philosophy and Science Teaching Group, the Association for Science Teacher Education (ASTE) and the National Association of Biology Teachers (NABT). Dr. McComas is widely published in the areas of the history and philosophy of science. He is a recipient of the Outstanding Evolution Educator award from NABT, the Ohaus award for innovations in College Science Teaching and the Outstanding Science Teacher Educator award from ASTE. He is interested in the improvement of laboratory instruction, evolution education, the interaction of the philosophy of science and science teaching, science for gifted students, and science instruction in museums and field sites.
I asked teachers on our Facebook page ”What would you want to know if you could ask a scientist how to explain anything?”
Our first question was about the concept of molecular polarity and how to explain its relation to VSEPR geometries. I brought this question to Jeff Levy, a teacher with his Master’s Degree in Chemical Engineering from Carnegie Mellon University and who has taught high school chemistry and physics at the Cranbrook Kingswood School in Michigan, the Horace Mann School in NYC, and The American School in London. I asked him about this concept and about how he teaches it to his students. Here is his answer:
In a nutshell the process goes like this:
Find the molecular geometry using VSEPR theory
Use electronegativity to decide if any bonds are polar
Use the geometry to decide if the polar bond vectors will add or cancel each other out.
VSEPR means this: electrons repel each other (that’s the E and the R) because of the electrostatic force. This repulsion dictates the arrangement or geometry of atoms within molecules. When you’re talking about molecular geometry then you only need to consider the bonding pairs and unbonded or “lone” pairs (that’s the P) of electrons that are located in the outer or “valence” shell (that’s the V and S) of each atom. Valence Shell Electron Pair Repulsion.
When teaching this I always started with gum drops and tooth picks and asked the kids “place X toothpicks in your gumdrop in such a way that all X of your toothpicks point as far away from each other as possible.” Eventually they come up with the proper geometries (once they start to think in 3D). I also demonstrated with balloons (tie 4 balloons together at the knot and they naturally form a tetrahedral geometry.)
And then, after you’ve figured out where the atoms are arranged in the molecule, you look at their relative electronegativities and decide where charges will aggregate and if the whole molecule will be polar.
I wish Angry Birds had been around when I was teaching high school physics. Please don’t think of the game as a hate crime against hogs, or an avian anger management program—instead, think of it as a computer interactive lab to explore projectile motion and force diagrams. Your students are playing it anyway, at least let them know that they are learning some physics along the way. Launching a bird? No! They are varying the initial angles and velocities to hit a target distance. Take advantage of student interest with the following strategies to help you integrate Angry Birds into your instruction.
Before Pythagoras (the equation, that is) even comes into the discussion, we should be asking our students to describe projectile motions that they see in their everyday lives. Focus on the big picture question: What are the different factors that determine the range of a projectile? Projectile motion problems can easily become algebra problems that focus on identifying the right number in a diagram and substituting it into the correct equation. We want them to see projectile motion in baseball games, long football throws (think the famous Hail Mary, game-winning touchdown pass by Dallas Cowboys quarterback Roger Staubach to Drew Pearson in a 1975 NFL playoff game), the human cannonball at the circus, rockets, and shooting hoops.
And then there is Angry Birds. The game actually helps your instruction by outlining the bird’s path with dots that are placed at the same time interval, as well as leaving these trajectory paths visible for the next turn. This allows for an overlap and visual comparison of bird trajectories that have different initial angles and velocities. I stress, the goal here is not to try and knock down the structures and take out the pigs, but to use the game platform as a demonstration tool that will get their attention, and to see the flying birds as your projectiles. In a later blog we will look at the structures for teaching force and motion.
Using Angry Birds, you can highlight many of the main points about projectile motion. Things like:
How do you get a bird to travel the farthest? Answer, 45-degree initial launch angle.
Can you find multiple launch angles that will land on the same spot? Answer, there are two per spot, and they are complementary angles.
What happens when you launch birds at the same angle but change the initial velocity?
What happens when you launch birds at the same velocity but change the initial angle?
What launch angles have the longest time in flight? The shortest?
The best levels to use for teaching projectile motion meet these criteria: good open field and no high structures to get in the way of the flight, use of the basic red birds, and having many birds to play with. Theme 1, levels 2 and 3 (see video at the beginning of this blog) offer many birds and a fairly open field for long-range projectiles. Videos of all levels can be found here.
In a Wired Science blog, Rhett Allain demonstrates how you can use a simple video tracker program to map the trajectory of the birds in these videos to actually calculate the size of the birds (with the assumption that gravity in the Angry Bird world is also 9.8 m/s^2). You will be surprised at the result—these red birds are BIG!
When NASA selected the first civilian to travel into space, it wasn’t a rock star or a journalist—it was a teacher. January 28, 2011 is the 25th anniversary of the Space Shuttle Challenger disaster, when seven explorers lost their lives doing something that they believed in. On January 28, 1986, I was a sixth grade student, and I’ll never forget the immediate silence that fell over my middle school cafeteria when the principal announced the event over the PA system during lunch. We all filed back to our classrooms to watch the television coverage for the rest of the school day.
Christa’s Portrait — Image from NASA
That event solidified in me what had been a growing desire that began when I was four years old and watched Carl Sagan champion the need to explore the stars in his Cosmos series. Ten years after Challenger, I graduated from college with a degree in Physics and Astronomy and took my first job teaching high school in the Bronx. I learned more science that first year of teaching, and found more inspiration trying to help my students’ explore their own questions, than I had ever considered possible.
In the wake of September 11, 2001, NASA reached out to New York City students and offered 52 student experiment modules that would travel on a Space Shuttle mission. I found myself working with a group of NYC middle school students to help them develop their own collection of experiments that we would pack and send off to be launched into space. The Space Shuttle became our classroom. As we watched the Space Shuttle carry our experiments into orbit on January 16, 2003, I finally felt like I was playing a small role in space exploration. This was mission STS-107, and it tragically would be the last flight of the Space Shuttle Columbia, which disintegrated on reentry into the atmosphere, killing all seven crew members.
As I faced the loss of another Space Shuttle, I found myself on the other side of sixth grade. Now responsible for helping a large group of sixth graders try to understand the enormity of what had happened, I reconnected with my Challenger experience. I found new inspiration in the words of Christa McAuliffe, a teacher from Concord, NH who was one of the seven crew members lost on Challenger—“I touch the future. I teach.”
It’s about teaching science passionately. It’s about sharing good ideas that work. It’s about exploring different perspectives and learning new techniques to inspire your students. This blog is a place for the science education community to find suggestions, reflections, and strategies that help teachers create a promising future through STEM education.