Search the California Content Standards

Title: HS-ESS2 Earth’s Systems

Performance Expectation: Use a model to describe how variations in the flow of energy into and out of Earth’s systems result in changes in climate. [Clarification Statement: Examples of the causes of climate change differ by timescale, over 1-10 years: large volcanic eruption, ocean circulation; 10-100s of years: changes in human activity, ocean circulation, solar output; 10-100s of thousands of years: changes to Earth's orbit and the orientation of its axis; and 10-100s of millions of years: long-term changes in atmospheric composition.] [Assessment Boundary: Assessment of the results of changes in climate is limited to changes in surface temperatures, precipitation patterns, glacial ice volumes, sea levels, and biosphere distribution.]

Disciplinary Core Idea(s):
ESS1.B: Earth and the Solar System Cyclical changes in the shape of Earth’s orbit around the sun, together with changes in the tilt of the planet’s axis of rotation, both occurring over hundreds of thousands of years, have altered the intensity and distribution of sunlight falling on the earth. These phenomena cause a cycle of ice ages and other gradual climate changes. (secondary to HS-ESS2-4) ESS2.A: Earth Materials and Systems The geological record shows that changes to global and regional climate can be caused by interactions among changes in the sun’s energy output or Earth’s orbit, tectonic events, ocean circulation, volcanic activity, glaciers, vegetation, and human activities. These changes can occur on a variety of time scales from sudden (e.g., volcanic ash clouds) to intermediate (ice ages) to very long-term tectonic cycles. ESS2.D: Weather and Climate The foundation for Earth’s global climate systems is the electromagnetic radiation from the sun, as well as its reflection, absorption, storage, and redistribution among the atmosphere, ocean, and land systems, and this energy’s re-radiation into space. Changes in the atmosphere due to human activity have increased carbon dioxide concentrations and thus affect climate.

Science & Engineering Practices: Developing and Using Models Use a model to provide mechanistic accounts of phenomena. Connections to Nature of Science: Scientific Knowledge is Based on Empirical Evidence Science arguments are strengthened by multiple lines of evidence supporting a single explanation.

Crosscutting Concepts: Cause and Effect Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.

California Environmental Principles and Concepts:
Principle III Natural systems proceed through cycles that humans depend upon, benefit from, and can alter. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both.

California Common Core State Standards Connections:
ELA/Literacy SL.11-12.5: Make strategic use of digital media (e.g., textual, graphical, audio, visual, and interactive elements) in presentations to enhance understanding of findings, reasoning, and evidence and to add interest. Mathematics MP.2: Reason abstractly and quantitatively. MP.4: Model with mathematics. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS3.A; HS.PS3.B; HS.LS2.C; HS.ESS1.C; HS.ESS3.C; HS.ESS3.D Articulation across grade-bands: MS.PS3.A; MS.PS3.B; MS.PS3.D; MS.PS4.B; MS.LS1.C; MS.LS2.B; MS.LS2.C; MS.ESS2.A; MS.ESS2.B; MS.ESS2.C; MS.ESS2.D; MS.ESS3.C; MS.ESS3.D

Title: HS-ESS3 Earth and Human Activity

Performance Expectation: Analyze geoscience data and the results from global climate models to make an evidence-based forecast of the current rate of global or regional climate change and associated future impacts to Earth's systems. [Clarification Statement: Examples of evidence, for both data and climate model outputs, are for climate changes (such as precipitation and temperature) and their associated impacts (such as on sea level, glacial ice volumes, or atmosphere and ocean composition).] [Assessment Boundary: Assessment is limited to one example of a climate change and its associated impacts.]

Disciplinary Core Idea(s):
ESS3.D: Global Climate Change Though the magnitudes of human impacts are greater than they have ever been, so too are human abilities to model, predict, and manage current and future impacts.

Science & Engineering Practices: Analyzing and Interpreting Data Analyze data using computational models in order to make valid and reliable scientific claims. Connections to Nature of Science: Scientific Investigations Use a Variety of Methods Science investigations use diverse methods and do not always use the same set of procedures to obtain data. New technologies advance scientific knowledge. Scientific Knowledge is Based on Empirical Evidence Science knowledge is based on empirical evidence. Science arguments are strengthened by multiple lines of evidence supporting a single explanation.

Crosscutting Concepts: Stability and Change Change and rates of change can be quantified and modeled over very short or very long periods of time. Some system changes are irreversible.

California Environmental Principles and Concepts:
Principle I The continuation and health of individual human lives and of human communities and societies depend on the health of the natural systems that provide essential goods and ecosystem services. Principle II The long-term functioning and health of terrestrial, freshwater, coastal, and marine ecosystems are influenced by their relationships with human societies. Principle III Natural systems proceed through cycles that humans depend upon, benefit from, and can alter. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both. Principle V Decisions affecting resources and natural systems are based on a wide range of considerations and decision-making processes.

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. RST.11-12.2: Determine the central ideas or conclusions of a text; summarize complex concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms. RST.11-12.7: Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem. Mathematics MP.2: Reason abstractly and quantitatively. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS3.B; HS.PS3.D; HS.LS1.C; HS.ESS2.D Articulation across grade-bands: MS.PS3.B; MS.PS3.D; MS.ESS2.A; MS.ESS2.D; MS.ESS3.B; MS.ESS3.C; MS.ESS3.D

Title: HS-ESS3 Earth and Human Activity

Performance Expectation: Use a computational representation to illustrate the relationships among Earth systems and how those relationships are being modified due to human activity. [Clarification Statement: Examples of Earth systems to be considered are the hydrosphere, atmosphere, cryosphere, geosphere, and/or biosphere. An example of the far-reaching impacts from a human activity is how an increase in atmospheric carbon dioxide results in an increase in photosynthetic biomass on land and an increase in ocean acidification, with resulting impacts on sea organism health and marine populations.] [Assessment Boundary: Assessment does not include running computational representations but is limited to using the published results of scientific computational models.]

Disciplinary Core Idea(s):
ESS2.D: Weather and Climate Current models predict that, although future regional climate changes will be complex and varied, average global temperatures will continue to rise. The outcomes predicted by global climate models strongly depend on the amounts of human-generated greenhouse gases added to the atmosphere each year and by the ways in which these gases are absorbed by the ocean and biosphere. (secondary to HS-ESS3-6) ESS3.D: Global Climate Change Through computer simulations and other studies, important discoveries are still being made about how the ocean, the atmosphere, and the biosphere interact and are modified in response to human activities.

Science & Engineering Practices: Using Mathematics and Computational Thinking Use a computational representation of phenomena or design solutions to describe and/or support claims and/or explanations.

Crosscutting Concepts: Systems and System Models When investigating or describing a system, the boundaries and initial conditions of the system need to be defined and their inputs and outputs analyzed and described using models.

California Environmental Principles and Concepts:
Principle I The continuation and health of individual human lives and of human communities and societies depend on the health of the natural systems that provide essential goods and ecosystem services. Principle II The long-term functioning and health of terrestrial, freshwater, coastal, and marine ecosystems are influenced by their relationships with human societies. Principle III Natural systems proceed through cycles that humans depend upon, benefit from, and can alter. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both. Principle V Decisions affecting resources and natural systems are based on a wide range of considerations and decision-making processes.

California Common Core State Standards Connections:
Mathematics MP.2: Reason abstractly and quantitatively. MP.4: Model with mathematics. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: HS.LS2.B; HS.LS2.C; HS.LS4.D; HS.ESS2.A Articulation across grade-bands: MS.LS2.C; MS.ESS2.A; MS.ESS2.C; MS.ESS3.C; MS.ESS3.D

Title: HS-LS2 Ecosystems: Interactions, Energy, and Dynamics

Performance Expectation: Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales. [Clarification Statement: Examples of mathematical representations include finding the average, determining trends, and using graphical comparisons of multiple sets of data.] [Assessment Boundary: Assessment is limited to provided data.]

Disciplinary Core Idea(s):
LS2.A: Interdependent Relationships in Ecosystems Ecosystems have carrying capacities, which are limits to the numbers of organisms and populations they can support. These limits result from such factors as the availability of living and nonliving resources and from such challenges such as predation, competition, and disease. Organisms would have the capacity to produce populations of great size were it not for the fact that environments and resources are finite. This fundamental tension affects the abundance (number of individuals) of species in any given ecosystem. LS2.C: Ecosystem Dynamics, Functioning, and Resilience A complex set of interactions within an ecosystem can keep its numbers and types of organisms relatively constant over long periods of time under stable conditions. If a modest biological or physical disturbance to an ecosystem occurs, it may return to its more or less original status (i.e., the ecosystem is resilient), as opposed to becoming a very different ecosystem. Extreme fluctuations in conditions or the size of any population, however, can challenge the functioning of ecosystems in terms of resources and habitat availability.

Science & Engineering Practices: Using Mathematics and Computational Thinking Use mathematical representations of phenomena or design solutions to support and revise explanations. Connections to Nature of Science: Scientific Knowledge is Open to Revision in Light of New Evidence Most scientific knowledge is quite durable, but is, in principle, subject to change based on new evidence and/or reinterpretation of existing evidence.

Crosscutting Concepts: Scale, Proportion, and Quantity Using the concept of orders of magnitude allows one to understand how a model at one scale relates to a model at another scale.

California Environmental Principles and Concepts:
Principle II The long-term functioning and health of terrestrial, freshwater, coastal, and marine ecosystems are influenced by their relationships with human societies. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both.

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. WHST.9–12.2.a–e: Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes. Mathematics MP.2: Reason abstractly and quantitatively. MP.4: Model with mathematics. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: HS.ESS2.E; HS.ESS3.A; HS.ESS3.C; HS.ESS3.D Articulation across grade-bands: MS.LS2.A; MS.LS2.C; MS.ESS3.C

Title: HS-LS2 Ecosystems: Interactions, Energy, and Dynamics

Performance Expectation: Evaluate claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem. [Clarification Statement: Examples of changes in ecosystem conditions could include modest biological or physical changes, such as moderate hunting or a seasonal flood; and extreme changes, such as volcanic eruption or sea level rise.]

Disciplinary Core Idea(s):
LS2.C: Ecosystem Dynamics, Functioning, and Resilience A complex set of interactions within an ecosystem can keep its numbers and types of organisms relatively constant over long periods of time under stable conditions. If a modest biological or physical disturbance to an ecosystem occurs, it may return to its more or less original status (i.e., the ecosystem is resilient), as opposed to becoming a very different ecosystem. Extreme fluctuations in conditions or the size of any population, however, can challenge the functioning of ecosystems in terms of resources and habitat availability.

Science & Engineering Practices: Engaging in Argument from Evidence Evaluate the claims, evidence, and reasoning behind currently accepted explanations or solutions to determine the merits of arguments. Connections to Nature of Science: Scientific Knowledge is Open to Revision in Light of New Evidence Scientific argumentation is a mode of logical discourse used to clarify the strength of relationships between ideas and evidence that may result in revision of an explanation.

Crosscutting Concepts: Stability and Change Much of science deals with constructing explanations of how things change and how they remain stable.

California Environmental Principles and Concepts:
Principle II The long-term functioning and health of terrestrial, freshwater, coastal, and marine ecosystems are influenced by their relationships with human societies. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both.

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. RST.11-12.7: Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem. RST.9-10.8: Assess the extent to which the reasoning and evidence in a text support the author’s claim or a recommendation for solving a scientific or technical problem. RST.11-12.8.a–e: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. Mathematics MP.2: Reason abstractly and quantitatively. S-ID.1: Represent data with plots on the real number line. S-IC.1: Understand statistics as a process for making inferences about population parameters based on a random sample from that population. S-IC.6: Evaluate reports based on data.

DCI Connections:
Connections to other DCIs in this grade-band: HS.ESS2.E Articulation across grade-bands: MS.LS2.A; MS.LS2.C; MS.ESS2.E; MS.ESS3.C

Title: HS-LS2 Ecosystems: Interactions, Energy, and Dynamics

Performance Expectation: Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.* [Clarification Statement: Examples of human activities can include urbanization, building dams, and dissemination of invasive species.]

Disciplinary Core Idea(s):
LS2.C: Ecosystem Dynamics, Functioning, and Resilience Moreover, anthropogenic changes (induced by human activity) in the environment—including habitat destruction, pollution, introduction of invasive species, overexploitation, and climate change—can disrupt an ecosystem and threaten the survival of some species. LS4.D: Biodiversity and Humans Biodiversity is increased by the formation of new species (speciation) and decreased by the loss of species (extinction). (secondary to HS-LS2-7) Humans depend on the living world for the resources and other benefits provided by biodiversity. But human activity is also having adverse impacts on biodiversity through overpopulation, overexploitation, habitat destruction, pollution, introduction of invasive species, and climate change. Thus sustaining biodiversity so that ecosystem functioning and productivity are maintained is essential to supporting and enhancing life on Earth. Sustaining biodiversity also aids humanity by preserving landscapes of recreational or inspirational value. (secondary to HS-LS2-7) (Note: This Disciplinary Core Idea is also addressed by HS-LS4-6.) ETS1.B: Developing Possible Solutions When evaluating solutions it is important to take into account a range of constraints including cost, safety, reliability and aesthetics and to consider social, cultural and environmental impacts. (secondary to HS-LS2-7)

Science & Engineering Practices: Constructing Explanations and Designing Solutions Design, evaluate, and refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations.

Crosscutting Concepts: Stability and Change Much of science deals with constructing explanations of how things change and how they remain stable.

California Environmental Principles and Concepts:
Principle II The long-term functioning and health of terrestrial, freshwater, coastal, and marine ecosystems are influenced by their relationships with human societies. Principle IV The exchange of matter between natural systems and human societies affects the long-term functioning of both.

California Common Core State Standards Connections:
ELA/Literacy RST.9-10.8: Assess the extent to which the reasoning and evidence in a text support the author’s claim or a recommendation for solving a scientific or technical problem. RST.11-12.7: Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem. RST.11-12.8.a–e: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. WHST.9-12.7: Conduct short as well as more sustained research projects to answer a question (including a self-generated question) or solve a problem; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, demonstrating understanding of the subject under investigation. Mathematics MP.2: Reason abstractly and quantitatively. N-Q.1-3: Reason quantitatively and use units to solve problems.

DCI Connections:
Connections to other DCIs in this grade-band: HS.ESS2.D; HS.ESS2.E; HS.ESS3.A; HS.ESS3.C Articulation across grade-bands: MS.LS2.C; MS.ESS3.C; MS.ESS3.D

Title: HS-PS4 Waves and Their Applications in Technologies for Information Transfer

Performance Expectation: Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model, and that for some situations one model is more useful than the other. [Clarification Statement: Emphasis is on how the experimental evidence supports the claim and how a theory is generally modified in light of new evidence. Examples of a phenomenon could include resonance, interference, diffraction, and photoelectric effect.] [Assessment Boundary: Assessment does not include using quantum theory.]

Disciplinary Core Idea(s):
PS4.A: Wave Properties [From the 3–5 grade band endpoints] Waves can add or cancel one another as they cross, depending on their relative phase (i.e., relative position of peaks and troughs of the waves), but they emerge unaffected by each other. (Boundary: The discussion at this grade level is qualitative only; it can be based on the fact that two different sounds can pass a location in different directions without getting mixed up.) PS4.B: Electromagnetic Radiation Electromagnetic radiation (e.g., radio, microwaves, light) can be modeled as a wave of changing electric and magnetic fields or as particles called photons. The wave model is useful for explaining many features of electromagnetic radiation, and the particle model explains other features.

Science & Engineering Practices: Engaging in Argument from Evidence Evaluate the claims, evidence, and reasoning behind currently accepted explanations or solutions to determine the merits of arguments. Connections to Nature of Science: Science Models, Laws, Mechanisms, and Theories Explain Natural Phenomena A scientific theory is a substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment and the science community validates each theory before it is accepted. If new evidence is discovered that the theory does not accommodate, the theory is generally modified in light of this new evidence.

Crosscutting Concepts: Systems and System Models Models (e.g., physical, mathematical, computer models) can be used to simulate systems and interactions—including energy, matter, and information flows—within and between systems at different scales.

California Environmental Principles and Concepts:
N/A

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. RST.9-10.8: Assess the extent to which the reasoning and evidence in a text support the author’s claim or a recommendation for solving a scientific or technical problem. RST.11-12.8: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. Mathematics MP.2: Reason abstractly and quantitatively. A-SSE.1.a-b: Interpret expressions that represent a quantity in terms of its context. A-SSE.3.a-c: Choose and produce an equivalent form of an expression to reveal and explain properties of the quantity represented by the expression. A.CED.4: Rearrange formulas to highlight a quantity of interest, using the same reasoning as in solving equations.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS3.D; HS.ESS1.A; HS.ESS2.D Articulation across grade-bands: MS.PS4.B

Title: HS-PS4 Waves and Their Applications in Technologies for Information Transfer

Performance Expectation: Evaluate the validity and reliability of claims in published materials of the effects that different frequencies of electromagnetic radiation have when absorbed by matter. [Clarification Statement: Emphasis is on the idea that photons associated with different frequencies of light have different energies, and the damage to living tissue from electromagnetic radiation depends on the energy of the radiation. Examples of published materials could include trade books, magazines, web resources, videos, and other passages that may reflect bias.] [Assessment Boundary: Assessment is limited to qualitative descriptions.]

Disciplinary Core Idea(s):
PS4.B: Electromagnetic Radiation When light or longer wavelength electromagnetic radiation is absorbed in matter, it is generally converted into thermal energy (heat). Shorter wavelength electromagnetic radiation (ultraviolet, X-rays, gamma rays) can ionize atoms and cause damage to living cells.

Science & Engineering Practices: Obtaining, Evaluating, and Communicating Information Evaluate the validity and reliability of multiple claims that appear in scientific and technical texts or media reports, verifying the data when possible.

Crosscutting Concepts: Cause and Effect Cause and effect relationships can be suggested and predicted for complex natural and human designed systems by examining what is known about smaller scale mechanisms within the system.

California Environmental Principles and Concepts:
N/A

California Common Core State Standards Connections:
ELA/Literacy RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. RST.9-10.8: Assess the extent to which the reasoning and evidence in a text support the author’s claim or a recommendation for solving a scientific or technical problem. RST.11-12.7: Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem. RST.11-12.8: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. WHST.11-12.8: Gather relevant information from multiple authoritative print and digital sources, using advanced searches effectively; assess the strengths and limitations of each source in terms of the specific task, purpose, and audience; integrate information into the text selectively to maintain the flow of ideas, avoiding plagiarism and overreliance on any one source and following a standard format for citation.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS1.C; HS.PS3.A; HS.PS3.D; HS.LS1.C Articulation across grade-bands: MS.PS3.D; MS.PS4.B; MS.LS1.C; MS.ESS2.D

Title: HS-PS4 Waves and Their Applications in Technologies for Information Transfer

Performance Expectation: Communicate technical information about how some technological devices use the principles of wave behavior and wave interactions with matter to transmit and capture information and energy.* [Clarification Statement: Examples could include solar cells capturing light and converting it to electricity; medical imaging; and communications technology.] [Assessment Boundary: Assessments are limited to qualitative information. Assessments do not include band theory.]

Disciplinary Core Idea(s):
PS3.D: Energy in Chemical Processes Solar cells are human-made devices that likewise capture the sun’s energy and produce electrical energy. (secondary to HS-PS4-5) PS4.A: Wave Properties Information can be digitized (e.g., a picture stored as the values of an array of pixels); in this form, it can be stored reliably in computer memory and sent over long distances as a series of wave pulses. PS4.B: Electromagnetic Radiation Photoelectric materials emit electrons when they absorb light of a high-enough frequency. PS4.C: Information Technologies and Instrumentation Multiple technologies based on the understanding of waves and their interactions with matter are part of everyday experiences in the modern world (e.g., medical imaging, communications, scanners) and in scientific research. They are essential tools for producing, transmitting, and capturing signals and for storing and interpreting the information contained in them.

Science & Engineering Practices: Obtaining, Evaluating, and Communicating Information Communicate technical information or ideas (e.g., about phenomena and/or the process of development and the design and performance of a proposed process or system) in multiple formats (including orally, graphically, textually, and mathematically).

Crosscutting Concepts: Cause and Effect Systems can be designed to cause a desired effect. Connections to Engineering, Technology, and Applications of Science: Interdependence of Science, Engineering, and Technology Science and engineering complement each other in the cycle known as research and development (R&D). Influence of Engineering, Technology, and Science on Society and the Natural World Modern civilization depends on major technological systems.

California Environmental Principles and Concepts:
N/A

California Common Core State Standards Connections:
ELA/Literacy WHST.9-10.2.a-f: Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes. WHST.11-12.2.a-e: Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.

DCI Connections:
Connections to other DCIs in this grade-band: HS.PS3.A Articulation across grade-bands: MS.PS4.A; MS.PS4.B; MS.PS4.C