Search the California Content Standards

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:
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:
Design and develop computational artifacts working in team roles using collaborative tools.

Descriptive Statement:
Collaborative tools can be as complex as a source code version control system or as simple as a collaborative word processor. Team roles in pair programming are driver and navigator but students can take on more specialized roles in larger teams. Teachers or students should choose resources that aid collaborative program development as programs grow more complex. For example, students might work as a team to develop a mobile application that addresses a problem relevant to the school or community, using appropriate tools to support actions such as: establish and manage the project timeline; design, share, and revise graphical user interface elements; implement program components, track planned, in-progress, and completed components, and design and implement user testing.

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:
Compare levels of abstraction and interactions between application software, system software, and hardware.

Descriptive Statement:
At its most basic level, a computer is composed of physical hardware on which software runs. Multiple layers of software are built upon various layers of hardware. Layers manage interactions and complexity in the computing system. System software manages a computing device's resources so that software can interact with hardware. Application software communicates with the user and the system software to accomplish its purpose. Students compare and describe how application software, system software, and hardware interact. For example, students could compare how various levels of hardware and software interact when a picture is to be taken on a smartphone. Systems software provides low-level commands to operate the camera hardware, but the application software interacts with system software at a higher level by requesting a common image file format (e.g., .png) that the system software provides.

Standard:
Demonstrate the flow of execution of a recursive algorithm.

Descriptive Statement:
Recursion is a powerful problem-solving approach where the problem solution is built on solutions of smaller instances of the same problem. A base case, which returns a result without referencing itself, must be defined, otherwise infinite recursion will occur. Students represent a sequence of calls to a recursive algorithm and show how the process resolves to a solution. For example, students could draw a diagram to illustrate flow of execution by keeping track of parameter and returned values for each recursive call. Alternatively, students could create a video showing the passing of arguments as the recursive algorithm runs.

Standard:
Plan and develop programs for broad audiences using a specific software life cycle process.

Descriptive Statement:
Software development processes are used to help manage the design, development, and product/project management of a software solution. Various types of processes have been developed over time to meet changing needs in the software landscape. The systems development life cycle (SDLC), also referred to as the application development life cycle, is a term used in systems engineering, information systems, and software engineering to describe a process for planning, creating, testing, and deploying an information system. Other examples of common processes could include agile, spiral, or waterfall. Students develop a program following a specific software life cycle process, with proper scaffolding from the teacher. For example, students could work in teams on a common project using the agile development process, which is based on breaking product development work into small increments. Alternatively, students could be guided in implementing sprints to focus work on daily standup meetings or scrums to support efficient communication.