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Classroom Perspectives on Curriculum

Teachers have always been essential partners in Project 2061’s science education reform efforts. Their contributions have been especially critical in the development of the Toward High School Biology (THSB) unit for middle school students and the Matter and Energy for Growth and Activity (MEGA) unit for high school biology students. Together, teachers and the Project 2061 curriculum development teams have worked to design engaging and effective learning experiences for students that achieve the vision of science teaching and learning in NGSS.  

In the accounts that follow, two teachers from a suburban school district—one who field tested the THSB middle school unit and one who field tested the high school biology MEGA unit—provide a look into today’s science classrooms. They offer firsthand reporting on their experiences with the units and with NGSS, how the units differ from previous materials they’ve used, and the impact the units have had on their own teaching and their students’ learning.

Sarah Pappalardo, middle school science teacher, participated in both early and late stages of testing the THSB unit and, along with other teachers in her district, continues to use the unit in her classroom. Probably the most dramatic difference between the NGSS-aligned approach of the THSB unit and the materials we used prior to NGSS is the integration of physical and life science ideas. This is a big change for teachers, especially for those who don’t have the appropriate coursework in their background and may not see the connections between chemistry and life science.  Now that we’re actually integrating life and physical science as we use THSB, it’s been a plus, especially for the kids. They find it more interesting to look at chemistry in the context of life processes, and that interest can pay off later in high school chemistry and biology. 

 Mass conservation in physical and living systems. At the middle school level, for example, the NGSS crosscutting concept of matter and energy focuses on the conservation of atoms in physical and chemical processes. But with the THSB unit, my students use this same concept of mass conservation to answer basic, but interesting, questions about plants and animals: How does a tiny seedling grow into a massive tree?  How does a small baby of only 7 or 8 pounds grow into a much larger middle school student?  The buildup to answering these questions starts with students exploring three common chemical reactions that many students had probably already experienced in real life: the “volcano” reaction of baking soda and vinegar, iron rusting when exposed to air, and the production of a polymer, in this case nylon fiber from the reaction of hexamethylenediamine and adipic acid. 

I call these reactions “sturdy” phenomena because students can use them to explore so many aspects of matter conservation. Kids used LEGOs to model the first two reactions, first in closed systems and then in open systems and considered whether anything was entering or leaving the system. They counted the LEGO blocks and then they weighed them to determine changes in mass. Nearly all my students, at all learning levels, could see that what you start with is what you end with, even if the LEGOs are connected in different ways or are now outside the system. I’m convinced that when kids really understand the basic underlying chemical processes, they have little trouble applying them to different contexts such as growth and repair in plants and animals. To me, that is the real goal of the crosscutting concepts in NGSS.

From science ideas to storyline. For many teachers, I think it’s not always clear how to incorporate all three dimensions of NGSS into their lessons. The THSB unit has made a kind of breakthrough in the way it creates a set of “science ideas” by combining disciplinary core ideas about matter, chemical reactions, and plant and animal growth with elements from the crosscutting concept of matter conservation.  These science ideas then make up the storyline for the entire unit, which adds to its coherence. And because the science ideas are made very explicit in the unit, students can cite the ideas—which students know to be widely accepted by scientists worldwide—to support claims in their explanations of phenomena. Students can also use the science ideas as a kind of summary of what they’ve been learning as they move through the lessons. For teachers, I think the science ideas remind them of the NGSS goals and help them keep track of what they should be emphasizing in class. 

All of this is in contrast to what I’ve seen other materials do. Most if not all of them may list the NGSS elements that they are aligning with, but I have not seen any other material that puts the NGSS elements together to build a storyline that progresses through the unit. Most are still using a “list and cover” approach that encourages teachers to just check off the different NGSS elements and not bother with making connections among them.  

Then and now. Prior to NGSS and THSB, the textbook we were using to teach middle school physical science took a very piecemeal approach to the topic of matter. It covered atoms, chemical formulas, reactions, and balancing equations but provided no hint as to why students should learn the content. There was no storyline to relate the physical science ideas that kids were learning to biology or to make any real-world connections. In one activity students made slime as an example of a polymer, but there was nothing in the text to connect that to the polymers that make up the bodies of plants and animals, something that would have been interesting to most kids. There were no phenomena on which to build students’ knowledge and, thus, no modeling activities or discussions to help students make sense of things. It was just lecturing at them and expecting them to remember everything. 

With NGSS and materials like THSB that take NGSS seriously, you see just how important it is for students to be able to experience science through the core ideas, the practices, and the crosscutting concepts.  Over the last few years, with the issue of climate change in the news, I always have at least a couple of students who have put two and two together about the role of CO2 in plant growth, and they ask, “Why can’t we just plant more trees to take care of the excess CO2 in the environment?” That leads to some far-reaching discussions about deforestation, carbon sinks in the oceans, and more. I’m sure that we would not be having these conversations prior to NGSS and THSB, so I think that’s a very good sign. 

Erin Schiff, high school special education teacher, works with the biology department in her high school to provide one-on-one support to special needs students and to co-teach lessons for the entire class. Prior to NGSS, biology classes I taught in mostly involved teachers lecturing and showing PowerPoint presentations and students completing worksheets and labs, memorizing content, and then simply restating it on tests. NGSS has taken us in a new direction, one that seems to be much more student-focused.  So far, most of my experience working with NGSS has come from participating in the field testing of the MEGA unit. Features of the unit, many inspired by NGSS, have turned out to be very engaging to most of the students I taught, whether they were special needs or not. 

Systems and system models. For example, the MEGA unit gave us an opportunity to work with the crosscutting concept of systems and system models. The idea of defining a system and representing it with different kinds of models helped many students grasp abstract concepts such as conservation of matter during chemical reactions. Students started with physical molecular models that let them actually count and weigh “atoms” before and after a simple chemical reaction so that they could account for every atom in the starting and ending substances.  Eventually, they defined various chemical reaction systems (e.g., the decomposition of water in a Petri dish and the surrounding system; a burning marshmallow and the surrounding system). Then students identified and quantified inputs and outputs to the systems as a way to explain changes in mass. 

By the time students encountered photosynthesis, they were ready to think about plants as another type of system and to consider the energy inputs and outputs of the plant system to account for atoms and molecules during the photosynthesis reaction.  The phenomena that students experienced actually highlighted the parallels between what happens in nonliving and living systems. For example, students first observed and explained why a solar-powered toy car moved faster under more intense light and then used the same ideas to explain why pondweed produced more bubbles as the rate of photosynthesis increased under more intense sunlight. The same kind of systems thinking was applied to growth and activity in the human body. This approach made a big difference for students, even for those non-traditional students who were not seeking a high school diploma. They were able to make connections and recall information, something I had not seen these students do before. 

Strategies to help all learners. As a special educator, my focus is always on the needs of the learner. Some of the strategies laid out in the MEGA unit were particularly useful in serving my special needs students. The use of visual models such as energy system boxes and energy transfer models helped to give special needs students a way to quantify, represent, and make sense of phenomena (e.g., energy-releasing and energy-requiring reactions) that would otherwise be invisible to them.  Visuals such as this can be especially important for English learners. In addition, the use of a limited but consistent vocabulary for describing both physical and life science phenomena was helpful for special needs students and probably for other students as well. 

The MEGA unit’s use of concrete examples to help students think about abstract molecular ideas of matter and energy changes in systems was a big contrast to the typical approach to teaching this content, which would usually start with memorizing formulas, balancing equations, and so on. When students were able to calculate and analyze their data themselves—e.g., the masses of the atoms involved in photosynthesis—they were much more engaged and able to understand what was happening. They were moving away from “it’s true because my teacher told me so” toward “I can use models to help me figure it out by myself.” 

Now that I’ve taught the MEGA unit for two years, I feel that I have a different understanding of the science and of NGSS. I am more comfortable now than at the beginning. I’m now working with a new 11th grade introductory chemistry/physics course that is aligned to NGSS. The course uses many of the same phenomena and models for energy changes within and between systems that we used with MEGA. It will be interesting to see what students who have used MEGA will bring to the new unit.

Both the THSB and MEGA units are available from NSTA Press. Their development was supported by grants from the U.S. Department of Education’s Institute of Education Sciences.



Mary Koppal

Communications Director

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