Our science curriculum is based on the four strands identified in Ready, Set, SCIENCE!: Putting Research to Work in K-8 Science Classrooms.  Published by The National Research Council of the National Academies. 

Four Strands of Science Learning

Strand 1: Understanding Scientific Explanations

To be proficient in science, students need to know, use, and interpret scientific explanations of the natural world. They must understand interrelations among central scientific concepts and use them to build and critique scientific arguments. This strand includes the things that are usually categorized as content, but it focuses on concepts and the links between them rather than on discrete facts. It also includes the ability to use this knowledge

Strand 2: Generating Scientific Evidence
Evidence is at the heart of scientific practice. Proficiency in science entails generating and evaluating evidence as part of building and refining models and explanations of the natural world. This strand includes things that might typically be thought of as “process,” but it shifts the notion to emphasize the theory and model-building aspects of science.
Strand 2 encompasses the knowledge and skills needed to build and refine models and explanations, design and analyze investigations, and construct and defend arguments with evidence. For example, this strand includes recognizing when there is insufficient evidence to draw a conclusion and determining what kind of additional data are needed.
This strand also involves mastering the conceptual, mathematical, physical, and computational tools that need to be applied in constructing and evaluating knowledge claims. Thus, it includes a wide range of practices involved in designing and carrying out a scientific investigation. These include asking questions, deciding what to measure, developing measures, collecting data from the measures, structuring the data, interpreting and evaluating the data, and using results to develop and refine arguments, models, and theories.


Strand 3: Reflecting on Scientific Knowledge  
Scientific knowledge builds on itself over time. Proficient science learners understand that scientific knowledge can be revised as new evidence emerges. They can also track and reflect on their own ideas as those ideas change over time. This strand includes ideas usually considered part of understanding the “nature of science,” such as the history of scientific ideas. However, it focuses more on how scientific knowledge is constructed. That is, how evidence and arguments based on that evidence are generated. It also includes students’ ability to reflect on the status of their own knowledge.
Strand 3 brings the nature of science into practice, encouraging students to learn what it feels like to do science as well as to understand what the game of science is all about. Strand 3 focuses on students’ understanding of science as a way of knowing. Scientific knowledge is a particular kind of knowledge with its own sources, justifications, and uncertainties. Students recognize that predictions or explanations can be revised on the basis of seeing new evidence, learning new facts, or developing a new model. In this way, students learn that they can subject their own knowledge to analysis.
When students understand the nature and development of scientific knowledge, they know that science entails searching for core explanations and the connections between them. Students recognize that there may be multiple interpretations of the same phenomenon. They understand that explanations are increasingly valuable as they account for the available evidence more completely. They also recognize the value of explanations in generating new and productive questions for research.

Strand 4: Participating Productively in Science  
Science is a social enterprise governed by a core set of values and norms for participation. Proficiency in science entails skillful participation in a scientific community in the classroom and mastery of productive ways of representing ideas, using scientific tools, and interacting with peers about science. This strand calls for students to understand the appropriate norms for presenting scientific arguments and evidence and to practice productive social interactions with peers in the context of classroom science investigations. It also includes the motivation and attitudes that provide a foundation for students to be actively and productively involved in science classrooms. Strand 4 puts science in motion and in social context, emphasizing the importance of doing science and doing it together in groups. Like scientists, science students benefit from sharing ideas with peers, building interpretive accounts of data, and working together to discern which accounts are most persuasive.
Strand 4 is often completely overlooked by educators, yet research indicates that it is a critical component of science learning, particularly for students from populations that are underrepresented in science. Students who see science as valuable and interesting tend to be good learners and participants in science. They believe that steady effort in understanding science pays off—not that some people understand science and other people never will.