Crosscutting Concepts

Crosscutting Concepts

Crosscutting concepts have value because they provide students with connections
and intellectual tools that are related across the differing areas of disciplinary
content and can enrich their application of practices and their understanding of core
ideas.


 1. Patterns. Observed patterns of forms and events guide organization and classification, and
they prompt questions about relationships and the factors that influence them.
2. Cause and effect: Mechanism and explanation. Events have causes, sometimes simple,
sometimes multifaceted. A major activity of science is investigating and explaining causal
relationships and the mechanisms by which they are mediated. Such mechanisms can then be
tested across given contexts and used to predict and explain events in new contexts.
3. Scale, proportion, and quantity. In considering phenomena, it is critical to recognize what is
relevant at different measures of size, time, and energy and to recognize how changes in scale,
proportion, or quantity affect a system’s structure or performance.
4. Systems and system models. Defining the system under study—specifying its boundaries and
making explicit a model of that system—provides tools for understanding and testing ideas that
are applicable throughout science and engineering.
5. Energy and matter: Flows, cycles, and conservation. Tracking fluxes of energy and matter
into, out of, and within systems helps one understand the systems’ possibilities and limitations.
6. Structure and function. The way in which an object or living thing is shaped and its
substructure determine many of its properties and functions.
7. Stability and change. For natural and built systems alike, conditions of stability and
determinants of rates of change or evolution of a system are critical elements of study.


 The development process of the standards provided insights into the
crosscutting concepts. These insights are shared in the following guiding principles.
Crosscutting concepts can help students better understand core ideas in science and
engineering. When students encounter new phenomena, whether in a science lab, field trip, or on
their own, they need mental tools to help engage in and come to understand the phenomena from a
scientific point of view. Familiarity with crosscutting concepts can provide that perspective. For
example, when approaching a complex phenomenon (either a natural phenomenon or a machine) an
approach that makes sense is to begin by observing and characterizing the phenomenon in terms of
patterns. A next step might be to simplify the phenomenon by thinking of it as a system and
modeling its components and how they interact. In some cases it would be useful to study how
energy and matter flow through the system, or to study how structure affects function (or
malfunction). These preliminary studies may suggest explanations for the phenomena, which could
be checked by predicting patterns that might emerge if the explanation is correct, and matching
those predictions with those observed in the real world.
Crosscutting concepts can help students better understand science and engineering practices.
Because the crosscutting concepts address the fundamental aspects of nature, they also inform the
way humans attempt to understand it. Different crosscutting concepts align with different practices,
and when students carry out these practices, they are often addressing one of these crosscutting
concepts. For example, when students analyze and interpret data, they are often looking for patterns
in observations, mathematical or visual. The practice of planning and carrying out an investigation
is often aimed at identifying cause and effect relationships: if you poke or prod something, what
will happen? The crosscutting concept of “Systems and System Models” is clearly related to the
practice of developing and using models.
Repetition in different contexts will be necessary to build familiarity. Repetition is counter to
the guiding principles the writing team used in creating performance expectations to reflect the core
ideas in the science disciplines. In order to reduce the total amount of material students are held
accountable to learn, repetition was reduced whenever possible.