Search the California Content Standards

Standard:
Develop programs for multiple computing platforms.

Descriptive Statement:
Humans use computers in various forms in their lives and work. Depending on the situation, software solutions are more appropriate or valuable when available on different computational platforms or devices. Students develop programs for more than one computing platform (e.g. desktop, web, or mobile). For example, students could develop a mobile app for a location-aware software product and a different program that is installed on a computer. Alternatively, students could create a browser-based product and make it accessible across multiple platforms or computers (e.g., email).

Standard:
Modify an existing program to add additional functionality and discuss intended and unintended implications.

Descriptive Statement:
Modularity and code reuse is key in modern software. However, when code is modified, the programmer should consider relevant situations in which this code might be used in other places. Students create and document modifications to existing programs that enhance functionality, and then identify, document, and correct unintended consequences. For example, students could take an existing a procedure that calculates the average of a set of numbers and returns an integer (which lacks precision) and modify it to return a floating-point number instead. The student would explain how the change might impact multiple scenarios.

Standard:
Use version control systems, integrated development environments (IDEs), and collaborative tools and practices (e.g., code documentation) while developing software within a group.

Descriptive Statement:
Software development is a process that benefits from the use of tools that manage complexity, iterative development, and collaboration. Large or complex software projects often require contributions from multiple developers. Version control systems and other collaborative tools and practices help coordinate the process and products contributed by individuals on a development team. An integrated development environment (IDE) is a program within which a developer implements, compiles or interprets, tests, debugs, and deploys a software project. Students use common software development and documentation support tools in the context of a group software development project. At this level, facility with the full functionality available in the collaborative tools is not expected. For example, students could use common version control systems to modify and improve code or revert to a previous code version. Alternatively, students could use appropriate IDEs to support more efficient code design and development. Additionally, students could use various collaboration, communication, and code documentation tools designed to support groups engaging in complex and interrelated work.

Standard:
Illustrate ways computing systems implement logic through hardware components.

Descriptive Statement:
Computing systems use processors (e.g., a central processing unit or CPU) to execute program instructions. Processors are composed of components that implement the logical or computational operations required by the instructions. AND, OR, and NOT are examples of logic gates. Adders are examples of higher-leveled circuits built using low-level logic gates. Students illustrate how modern computing devices are made up of smaller and simpler components which implement the logic underlying the functionality of a computer processor. At this level, knowledge of how logic gates are constructed is not expected. For example, students could construct truth tables, draw logic circuit diagrams, or use an online logic circuit simulator. Students could explore the interaction of the CPU, RAM, and I/O by labeling a diagram of the von Neumann architecture. Alternatively, students could design higher-level circuits using low-level logic gates (e.g., adders).

Standard:
Use data analysis tools and techniques to identify patterns in data representing complex systems.

Descriptive Statement:
Data analysis tools can be useful for identifying patterns in large amounts of data in many different fields. Computers can help with the processing of extremely large sets of data making very complex systems manageable. Students use computational tools to analyze, summarize, and visualize a large set of data. For example, students could analyze a data set containing marathon times and determine how age, gender, weather, and course features correlate with running times. Alternatively, students could analyze a data set of social media interactions to identify the most influential users and visualize the intersections between different social groups.

Standard:
Evaluate the ability of models and simulations to test and support the refinement of hypotheses.

Descriptive Statement:
A model could be implemented as a diagram or a program that represents key properties of a physical or other system. A simulation is based on a model, and enables observation of the system as key properties change. Students explore, explain, and evaluate existing models and simulations, in order to support the refinement of hypotheses about how the systems work. At this level, the ability to accurately and completely model and simulate complex systems is not expected. For example, a computer model of ants following a path created by other ants who found food explains the trail-like travel patterns of the insect. Students could evaluate if the output of the model fits well with their hypothesis that ants navigate the world through the use of pheromones. They could explain how the computer model supports this hypothesis and how it might leave out certain aspects of ant behavior and whether these are important to understanding ant travel behavior. Alternatively, students could hypothesize how different ground characteristics (e.g., soil type, thickness of sediment above bedrock) relate to the severity of shaking at the surface during an earthquake. They could add or modify input about ground characteristics into an earthquake simulator, observe the changed simulation output, and then evaluate their hypotheses.

Standard:
Examine the scalability and reliability of networks, by describing the relationship between routers, switches, servers, topology, and addressing.

Descriptive Statement:
Choice of network topology is determined, in part, by how many devices can be supported and the character of communication needs between devices. Each device is assigned an address that uniquely identifies it on the network. Routers function by comparing addresses to determine how information on the network should reach its desgination. Switches compare addresses to determine which computers will receive information. Students explore and explain how network performance degrades when various factors affect the network. For example, students could use online network simulators to describe how network performance changes when the number of devices increases. Alternatively, students could visualize and describe changes to the distribution of network traffic when a router on the network fails.

Standard:
Develop solutions to security threats.

Descriptive Statement:
Designing and implementing cybersecurity measures requires knowledge of software, hardware, and human components and understanding tradeoffs. Students design solutions to security threats and compare tradeoffs of easier access and use against the costs of losing information and disrupting services. For example, students could refine a technology that allows users to use blank or weak passwords. Alternatively, students could implement a firewall or proxy protection between an organization's private local area network (LAN) and the public Internet. Additionally, students could find and close exploitable threats on an infected computer in order to protect information.

Standard:
Analyze cryptographic techniques to model the secure transmission of information.

Descriptive Statement:
Cryptography is essential to many models of cybersecurity. Open standards help to ensure cryptographic security. Certificate Authorities (CAs) issue digital certificates that validate the ownership of encrypted keys used in secured communications across the Internet. Students encode and decode messages using encryption and decryption methods, and they should understand the different levels of complexity to hide or secure information. For example, students could analyze the relative designs of private key vs. public key encryption techniques and apply the best choice for a particular scenario. Alternatively, students could analyze the design of the Diffie-Helman algorithm to RSA (Rivest–Shamir–Adleman) and apply the best choice for a particular scenario. They could provide a cost-benefit analysis of runtime and ease of cracking for various encryption techniques which are commonly used to secure transmission of data over the Internet.