Develop Models First! Vocabulary Later!

September 8, 2022

Develop Models First! Vocabulary Later!

Check out a few ideas on how to introduce new topics to students, like Ionic and Covalent Bonding, Newton’s Third Law, and Cellular Respiration.

As teachers, we want science to mean more than a list of terms and definitions that students memorize. We want our students to develop powerful mental models for scientific concepts. These mental models should allow students to explain phenomena and make accurate predictions.  Students need to observe, explore, measure, analyze, and use this experience to develop these scientific mental models. Simply telling students or having them memorize vocabulary words is not enough.

It can be challenging for teachers to provide opportunities for students to actively engage with phenomena in a way that lets students use their own observations to build mental models. The demands of teaching multiple courses, limited supply budgets, lack of training, and the myriad tasks associated with teaching prevent teachers from using best practices for active learning.

Pivot Interactives lets students actively engage with real phenomena, even when they have limited prior knowledge of a new concept. More, it does not require the hours of teacher set-up and take-down needed for traditional active learning. Classroom-ready activities based on interactive video draw students’ attention to the science at hand, encouraging them to make measurements and observations and to explore and look for patterns.  Pivot Interactives activities take only a few minutes for teachers to deploy. They allow students to begin their study of a new topic with rich, engaging, data-filled activities that guide students as they use their own observations and scientific reasoning to develop and test models.

Here are some examples of how Pivot Interactive enables active learning when students are being introduced to new topics: Ionic and Covalent Bonding, Newton’s Third Law, and Cellular Respiration.

It can be challenging for teachers to provide opportunities for students to actively engage with phenomena in a way that lets students use their own observations to build mental models.

Ionic and Covalent Bonding

Here’s an example of a passive lecture introduction to covalent bonding. This one is from Khan Academy’s video Ionic, Covalent, and Metallic Bonds. Why use a lecture when an effective, engaging, active learning alternative is readily available?
This is how covalent bonding is often introduced during a passive lecture. Why use a lecture when an effective, engaging, active learning alternative is readily available?

Bonding is a chemistry topic that is often introduced via lecture. Students learn the words, and view particle diagrams, hear about shared or exchanged electrons, but they often have no experience to help see how these ideas manifest in their world.

But what if students can make observations of the properties of ionic and molecular substances, and use these observations to see the difference between ionic and covalent bonds? Then, as students learn the underlying cause of ionic and covalent bonding, they have a context, some experience, as a framework for these ideas.

The Ionic and Covalent Bonding activity lets students use melting point and conductivity to categorize substances and make predictions as they build a scientific model based on these types of chemical bonds. This is active learning at its best, avai…
The Ionic and Covalent Bonding activity lets students use melting point and conductivity to categorize substances and make predictions as they build a scientific model based on these types of chemical bonds. This is active learning at its best, available in minutes.

The Pivot Interactives Ionic and Covalent Bonding activity allows students to observe the conductivity of aqueous solutions of many different compounds. In addition, students can compare the melting points using an engaging video showing each substance placed on a thermocouple and heated until it melts. Students are guided through a series of questions to discover the pattern: substances with a metal and a non-metal atom combined act differently from substances comprising only non-metals. Next, students use their newfound knowledge to test the pattern by making (and testing) predictions of the properties of substances. Finally, students are introduced to the terms ionic and covalent bonding to name the two types of bonding whose properties they have observed. This activity lets students actively engage in their learning, and use their own observations to begin to build a model that they can use to understand many phenomena.

Newton’s Third Law

“For every action there is an equal and opposite reaction” every high school student can easily recite Newton’s third law of motion. But if you ask probing questions, it’s common to find that students have misconceptions about this fundamental concept. Decades of physics education research has shown that lectures do little to displace students’ misconceptions.

Certainly, some hands-on demos can help. For example, students can link force gauges together and pull in opposite directions. They can try to observe that the forces on both spring scales is the same. But even this tends to be fragile knowledge. Ask them what would happen if one person pulls suddenly, or if the other person lets go of the force sensor, and students are often confused and revert to preconceptions.

This activity lets students see that the repulsion of these balloons is equal, even if the charge placed on them is not. Students see for themselves that forces between objects are always symmetrical.
This activity lets students see that the repulsion of these balloons is equal, even if the charge placed on them is not. Students see for themselves that forces between objects are always symmetrical.

Pivot Interactives has two activities to introduce Newton’s third law. First, students observe the effects of electric repulsion on two balloons. Students can adjust the charges on the balloons changing which balloon has a greater charge. Then, students use a protractor to measure the deflection of each balloon from vertical, showing how much electric force is acting on the balloon.  While changing the amount of force will create a greater force on the balloons, the deflection of the balloons is always symmetrical, showing that the amount of force the balloons exert on each other is also symmetrical, even if the amount of charge on the balloons is not equal. This activity helps students understand that the nature of electric repulsion is that it is symmetrical. It is this symmetry that leads to the macroscopically observable forces we see when objects come into contact with each other.

forces during collisions 2.jpg

In the next activity, students use high-speed video to observe and compare the forces acting on two objects during a collision. Springs on each object deflect during the collision, and students use an interactive ruler to measure the deflection. Students begin by comparing the force each object exerts on the other during the collision of equal mass objects moving towards each other at the same speed. They’ll see that the springs on each object deflect the same amount during the collision. Students usually assume that this is because the objects have the same mass and speed. But students can then select different videos where the objects have different masses and move at different speeds. Through observations and measurements, multiple trials, and discussions with their peers, students will determine that no matter what combination of masses and speeds, the force that each object exerts on the other is the same. The combination of these two activities provides compelling evidence that the forces objects exert on each other are always symmetrical.

This is active learning at its finest.

This is active learning at its finest. Students explore on their own, discuss their findings with peers, and use their experience to build knowledge. Moreover, these auto-graded activities take just minutes for teachers to deploy, providing instant feedback.

Introduction to Cellular Respiration

A typical lecture introduction to cellular respiration, starting with a definition. This is from Khan Academy’s video Introduction to Cellular Respiration. Cellular respiration is fascinating! Why learn with a lecture when students can observe cellu…
A typical lecture introduction to cellular respiration, starting with a definition. This is from Khan Academy’s video Introduction to Cellular Respiration. Cellular respiration is fascinating! Why learn with a lecture when students can observe cellular respiration themselves using Pivot Interactives?

For many students, their introduction to cellular respiration is a lecture or textbook reading starting with a definition. The lecture or text may go on to explain the importance of cellular respiration, and it’s role in the metabolism of many organisms. While these passive learning methods are common, most teachers and students would prefer a more active, engaging way to learn about this important topic.

What about having students introduced to the phenomena of cellular respiration by observing organisms and their metabolism? More, what if students were able to measure for themselves the changes in gas levels and see the energy produced for a wide range of organisms, from fungus to fish, germinating seeds to reptiles and mammals? Then, after students have observed the phenomena, and described the key attributes, only then are they introduced to the phrase “cellular respiration”. This way the term is a label for an idea that the students already have experience with. Students have developed a mental model for the phenomenon, so the name has a purpose.

Students observe increases in carbon dioxide and decrease in oxygen for seven organisms from mold, fish, and humans. Students quickly see similarities in the metabolism of seemingly unrelated organisms.
In the Pivot Interactives Introduction to Cellular Respiration activity, students observe increases in carbon dioxide and decrease in oxygen for seven organisms from mold, fish, and humans. Students quickly see similarities in the metabolism of seemingly unrelated organisms.

Practically speaking, it’s not easy to set up apparatus to allow students to observe and measure the effects of cellular respiration for even a single organism. Observing the carbon dioxide gas produced during cellular respiration by organisms like peas, yeast, or even crickets using a sensor or using a universal indicator is one option. But this takes hours to set up and it may take an entire class period for students to make a few observations. Even if this activity is successful,  students still won’t have seen how this extends to show how other organisms act, or to see both the increase in carbon dioxide gas and the decrease in oxygen that together signal cellular respiration.

Pivot Interactives has an Introduction to Cellular Respiration activity that allows students to observe and measure changes in carbon dioxide and oxygen gas for eight different organisms: mold, mushrooms, germinating peas, crickets, a mouse, a human, a tortoise, and fish. Gathering evidence that all these organisms consume oxygen and produce carbon dioxide allows students to see for themselves how fundamentally important this process is, that it underlies the metabolism of so many seemingly dissimilar organisms.

Teachers want to use active learning with students.

Teachers want to use active learning with students. They want students to be engaged and exploring, rather than passively listening and taking notes.  But the demands and constraints of teaching prevent teachers from using active learning as often as they would like. These activities provide unique opportunities for students to build knowledge from their own experiences. Teachers can deploy them quickly and automatic grading gives teachers and students instant feedback.

Do you want to know more, or try Pivot Interactives with your students?  Sign up for a free trial!