Search the California Content Standards

Standard:
Design algorithms to solve computational problems using a combination of original and existing algorithms.

Descriptive Statement:
Knowledge of common algorithms improves how people develop software, secure data, and store information. Some algorithms may be easier to implement in a particular programming language, work faster, require less memory to store data, and be applicable in a wider variety of situations than other algorithms. Algorithms used to search and sort data are common in a variety of software applications. For example, students could design an algorithm to calculate and display various sports statistics and use common sorting or mathematical algorithms (e.g., average) in the design of the overall algorithm. Alternatively, students could design an algorithm to implement a game and use existing randomization algorithms to place pieces randomly in starting positions or to control the "roll" of a dice or selection of a "card" from a deck.

Standard:
Justify the selection of specific control structures by identifying tradeoffs associated with implementation, readability, and performance.

Descriptive Statement:
The selection of control structures in a given programming language impacts readability and performance. Readability refers to how clear the program is to other programmers and can be improved through documentation. Control structures at this level may include, for example, conditional statements, loops, event handlers, and recursion. Students justify control structure selection and tradeoffs in the process of creating their own computational artifacts. The discussion of performance is limited to a theoretical understanding of execution time and storage requirements; a quantitative analysis is not expected. For example, students could compare the readability and program performance of iterative and recursive implementations of procedures that calculate the Fibonacci sequence. Alternatively, students could compare the readability and performance tradeoffs of multiple if statements versus a nested if statement.

Standard:
Iteratively design and develop computational artifacts for practical intent, personal expression, or to address a societal issue by using events to initiate instructions.

Descriptive Statement:
In this context, relevant computational artifacts can include programs, mobile apps, or web apps. Events can be user-initiated, such as a button press, or system-initiated, such as a timer firing. For example, students might create a tool for drawing on a canvas by first implementing a button to set the color of the pen. Alternatively, students might create a game where many events control instructions executed (e.g., when a score climbs above a threshold, a congratulatory sound is played; when a user clicks on an object, the object is loaded into a basket; when a user clicks on an arrow key, the player object is moved around the screen).

Standard:
Create computational artifacts using modular design.

Descriptive Statement:
Computational artifacts are created by combining and modifying existing computational artifacts and/or by developing new artifacts. To reduce complexity, large programs can be designed as systems of interacting modules, each with a specific role, coordinating for a common overall purpose. Students should create computational artifacts with interacting procedures, modules, and/or libraries. For example, students could incorporate a physics library into an animation of bouncing balls. Alternatively, students could integrate open-source JavaScript libraries to expand the functionality of a web application. Additionally, students could create their own game to teach Spanish vocabulary words using their own modular design (e.g., including methods to: control scoring, manage wordlists, manage access to different game levels, take input from the user, etc.).

Standard:
Systematically design programs for broad audiences by incorporating feedback from users.

Descriptive Statement:
Programmers use a systematic design and review process to meet the needs of a broad audience. The process includes planning to meet user needs, developing software for broad audiences, testing users from a cross-section of the audience, and refining designs based on feedback. For example, students could create a user satisfaction survey and brainstorm distribution methods to collect feedback about a mobile application. After collecting feedback from a diverse audience, students could incorporate feedback into their product design. Alternatively, while developing an e-textiles project with human touch sensors, students could collect data from peers and identify design changes needed to improve usability by users of different needs.

Standard:
Explain the limitations of licenses that restrict use of computational artifacts when using resources such as libraries.

Descriptive Statement:
Software licenses include copyright, freeware, and open-source licensing schemes. Licenses are used to protect the intellectual property of the author while also defining accessibility of the code. Students consider licensing implications for their own work, especially when incorporating libraries and other resources. For example, students might consider two software libraries that address a similar need, justifying their choice of one over the other. The choice could be based upon least restrictive licensing or further protections for their own intellectual property.

Standard:
Iteratively evaluate and refine a computational artifact to enhance its performance, reliability, usability, and accessibility.

Descriptive Statement:
Evaluation and refinement of computational artifacts involves measuring, testing, debugging, and responding to the changing needs and expectations of users. Aspects that can be evaluated include correctness, performance, reliability, usability, and accessibility. For example, after witnessing common errors with user input in a computational artifact, students could refine the artifact to validate user input and provide an error message if invalid data is provided. Alternatively, students could observe a robot in a variety of lighting conditions to determine whether the code controlling a light sensor should be modified to make it less sensitive. Additionally, students could also incorporate feedback from a variety of end users to help guide the size and placement of menus and buttons in a user interface.

Standard:
Document decisions made during the design process using text, graphics, presentations, and/or demonstrations in the development of complex programs.

Descriptive Statement:
Complex programs are often iteratively designed as systems of interacting modules, each with a specific role, coordinating for a common overall purpose. Comments are included in code both to document the purpose of modules as well as the implementation details within a module. Together these support documentation of the design process. Students use resources such as libraries and tools to edit and manage parts of the program and corresponding documentation. For example, during development of a computational artifact students could comment their code (with date, modification, and rationale), sketch a flowchart to summarize control flow in a code journal, and share ideas and updates on a white board. Students may document their logic by explaining the development process and presenting to the class. The presentation could include photos of their white board, a video or screencast explaining the development process, or recorded audio description.

Standard:
Describe the design characteristics of the Internet.

Descriptive Statement:
The Internet connects devices and networks all over the world. Large-scale coordination occurs among many different machines across multiple paths every time a web page is opened or an image is viewed online. Through the domain name system (DNS), devices on the Internet can look up Internet Protocol (IP) addresses, allowing end-to-end communication between devices. The design decisions that direct the coordination among systems composing the Internet also allow for scalability and reliability. Students factor historical, cultural, and economic decisions in their explanations of the Internet. For example, students could explain how hierarchy in the DNS supports scalability and reliability. Alternatively, students could describe how the redundancy of routing between two nodes on the Internet increases reliability and scales as the Internet grows.

Standard:
Compare and contrast security measures to address various security threats.

Descriptive Statement:
Network security depends on a combination of hardware, software, and practices that control access to data and systems. The needs of users and the sensitivity of data determine the level of security implemented. Potential security problems, such as denial-of-service attacks, ransomware, viruses, worms, spyware, and phishing, present threats to sensitive data. Students compare and contrast different types of security measures based on factors such as efficiency, feasibility, ethical impacts, usability, and security. At this level, students are not expected to develop or implement the security measures that they discuss. For example, students could review case studies or current events in which governments or organizations experienced data leaks or data loss as a result of these types of attacks. Students could provide an analysis of actual security measures taken comparing to other security measure which may have led to different outcomes. Alternatively, students might discuss computer security policies in place at the local level that present a tradeoff between usability and security, such as a web filter that prevents access to many educational sites but keeps the campus network safe.