Level 3A: Grades 9-10 (Ages 14-16)

Computing Systems

Networks & the Internet

Data & Analysis

Algorithms & Programming

Impacts of Computing

Note: Following are the CSTA Standards (performance expectations) with California modified descriptive statements and identified cross-curricular standards alignments with NGSS, CCSS, etc.

Explain how abstractions hide the underlying implementation details of computing systems embedded in everyday objects.

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

Develop guidelines that convey systematic troubleshooting strategies that others can use to identify and fix errors.

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

Give examples to illustrate how sensitive data can be affected by malware and other attacks.

Recommend security measures to address various scenarios based on factors such as efficiency, feasibility, and ethical impacts.

Compare various security measures, considering tradeoffs between the usability and security of a computing system.

Explain tradeoffs when selecting and implementing cybersecurity recommendations.

Translate between different representations of data abstractions of real-world phenomena, such as characters, numbers, and images.

Evaluate the tradeoffs in how data elements are organized and where data is stored.

Create interactive data visualizations using software tools to help others better understand real-world phenomena.

Create computational models that represent the relationships among different elements of data collected from a phenomenon or process.

Create prototypes that use algorithms to solve computational problems by leveraging prior student knowledge and personal interests.

Use lists to simplify solutions, generalizing computational problems instead of repeatedly using simple variables.

Justify the selection of specific control structures when trade-offs involve implementation, readability, and program performance, and explain the benefits and drawbacks of choices made.

Design and iteratively develop computational artifacts for practical intent, personal expression, or to address a societal issue by using events to initiate instructions.

Decompose problems into smaller sub-problems through systematic analysis, using constructs such as procedures, modules, and/or objects.

Create artifacts by using procedures within a program, combinations of data and procedures, or independent but interrelated programs.

Systematically design and develop programs for broad audiences by incorporating feedback from users.

Evaluate licenses that limit or restrict use of computational artifacts when using resources such as libraries.

Evaluate and refine computational artifacts to make them more usable and accessible.

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

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

Evaluate the ways computing impacts personal, ethical, social, economic, and cultural practices.

Test and refine computational artifacts to reduce bias and equity deficits.

Demonstrate ways a given algorithm applies to problems across disciplines.

Use tools and methods for collaboration on a project to increase connectivity of people in different cultures and career fields.

Explain the beneficial and harmful effects that intellectual property laws can have on innovation.

Explain the privacy concerns related to the collection and generation of data through automated processes that may not be evident to users.

Evaluate the social and economic implications of privacy in the context of safety, law, or ethics.

Levels 1A, 1B, 2, and 3A are the computer science standards for ALL students. The Level 3B standards are intended for students who wish to pursue the study of computer science in high school beyond what is required for all students (specialty or elective courses). 

Computing devices are often integrated with other systems, including biological, mechanical, and social systems. A medical device can be embedded inside a person to monitor and regulate his or her health, a hearing aid (a type of assistive device) can filter out certain frequencies and magnify others, a monitoring device installed in a motor vehicle can track a person’s driving patterns and habits, and a facial recognition device can be integrated into a security system to identify a person. The creation of integrated or embedded systems is not an expectation at this level. Students might select an embedded device such as a car stereo, identify the types of data (radio station presets, volume level) and procedures (increase volume, store/recall saved station, mute) it includes, and explain how the implementation details are hidden from the user.

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.

Troubleshooting complex problems involves the use of multiple sources when researching, evaluating, and implementing potential solutions. Troubleshooting also relies on experience, such as when people recognize that a problem is similar to one they have seen before and adapt solutions that have worked in the past. For example, students could create a list of troubleshooting strategies to debug network connectivity problems such as checking hardware and software status and settings, rebooting devices, and checking security settings. Alternatively, students could create troubleshooting guidelines for help desk employees based on commonly observed problems (e.g., problems connecting a new device to the computer, problems printing from a computer to a network printer).

Each device is assigned an address that uniquely identifies it on the network. Routers function by comparing IP addresses to determinethe pathways packets should take to reach their destination. Switches function by comparing MAC addresses to determine which computers or network segments will receive frames. Students could use online network simulators to experiment with these factors.

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 might reflect on case studies or current events in which governments or organizations experienced data leaks or data loss as a result of these types of attacks.

Security measures may include physical security tokens, two-factor authentication, and biometric verification. Potential security problems,such as denial-of-service attacks, ransomware, viruses, worms, spyware, and phishing, exemplify why sensitive data should be securely stored and transmitted. The timely and reliable access to data and information services by authorized users, referred to as availability, is ensured through adequate bandwidth, backups, and other measures. Students should systematically evaluate the feasibility of using computational tools to solve given problems or subproblems, such as through a cost-benefit analysis. Eventually, students should include more factors in their evaluations, such as how efficiency affects feasibility or whether a proposed approach raises ethical concerns.

Security measures may include physical security tokens, two-factor authentication, and biometric verification, but choosing security measures involves tradeoffs between the usability and security of the system. The needs of users and the sensitivity of data determine the level of security implemented. Students mightdiscuss 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.

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. Every security measure involves tradeoffs between the accessibility and security of the system. Students should be able to describe, justify, and document choices they make using terminology appropriate for the intended audience and purpose. Students could debate issues from the perspective of diverse audiences, including individuals, corporations, privacy advocates, security experts, and government.

Computers represent complex real-world concepts such as characters, numbers, and images through various abstractions. Students translate between these different levels of data representations. For example, students could convert an HTML (Hyper Text Markup Language) tag for red font into RGB (Red Green Blue), HEX (Hexadecimal Color Code), HSL (Hue Saturation Lightness), RGBA( Red Green Blue Alpha), or HSLA (Hue Saturation Lightness and Alpha) representations. Alternatively, students could convert the standard representation of a character such as ! into ASCII or Unicode.

People make choices about how data elements are organized and where data is stored. These choices affect cost, speed, reliability, accessibility, privacy, and integrity. Students describe implications for a given data organziation or storage choice in light of a specific problem. For example, students might consider the cost, speed, reliability, accessibility, privacy, and integrity tradeoffs between storing photo data on a mobile device versus in the cloud. Alternatively, students might compare the tradeoffs between file size and image quality of various image file formats and how choice of format may be infuenced by the device on which it is to be accessed (e.g., smartphone, computer).

People transform, generalize, simplify, and present large data sets in different ways to influence how other people interpret and understand the underlying information. Students select relevant data from large or complex data sets in support of a claim or to communicate the information in a more sophisticated manner. Students use software tools or programming to perform a range of mathematical operations to transform and analyze data and create powerful data visualizations (that reveal patterns in the data). For example, students could create data visualizations to reveal patterns in voting data by state, gender, political affiliation, or socioeconomic status. Alternatively, students could use U.S. government data on criticially endangered animals to visualize population change over time.

Computational models are used to make predictions about processes or phenomena based on selected data and features. They allow people to investigate the relationships among different variables to understand a system. Predictions are tested to validate models. Students evaluate these models against real-world observations. For example, students could use a population model that allows them to speculate about interactions among different species, evaluate the model based on data gathered from nature, and then refine the model to reflect more complex and realistic interactions.

A prototype is a computational artifact that demonstrates the core functionality of a product or process. Prototypes are useful for getting early feedback in the design process, and can yield insight into the feasibility of a product. The process of developing computational artifacts embraces both creative expression and the exploration of ideas to create prototypes and solve computational problems. Students create artifacts that are personally relevant or beneficial to their community and beyond. Students should develop artifacts in response to a task or a computational problem that demonstrate the performance, reusability, and ease of implementation of an algorithm.

Students should be able to identify common features in multiple segments of code and substitute a single segment that uses lists (arrays) to account for the differences.

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.

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. At previous levels, students have learned to create and call procedures. Here, students design procedures that are called by events. For example, students might create a mobile app that updates a list of nearby points of interest when the device detects that its location has been changed, or 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).

Decomposition enables solutions to complex problems to be designed and implemented as more manageable subproblems. Students decompose a given problem into subproblems that can be solved using existing functionalities, or new functionalities that they design and implement. For example, students could design a program for supporting soccer coaches in analyzing their teams' statistics. They decompose the problem in terms of managing input, analysis, and output. They decompose the data organization by designing what data will be stored per player, per game, and per team. Team players may be stored as a collection. Data per team player may include: number of shots, misses, saves, assists, penalty kicks, blocks, and corner kicks. Students design methods for supporting various statistical analyses and display options. Students design output formats for individual players or coaches.

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.).

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.

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.

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.

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.

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.

Computing may improve, harm, or maintain practices. An understanding of how equity deficits, such as minimal exposure to computing, access to education, and training opportunities, are related to larger, systemic problems in society enables students to create more meaningful artifacts. Students illustrate the positive, negative, and/or neutral impacts of computing. For example, students could evaluate the accessibility of a product for a broad group of end users, such as people who lack access to broadband or who have various disabilities. Students could identify potential bias during the design process and evaluate approaches to maximize accessibility in product design. Alternatively, students could evaluate the impact of social media on cultural, economic, and social practices around the world.

Biases could include incorrect assumptions developers have made about their users, including minimal exposure to computing, access to education, and training opportunities. Students identify and use strategies to test and refine computational artifacts with the goal of reducing bias and equity deficits and increasing universal access. For example, students could use a spreadsheet to chart various forms of equity deficits, and identify solutions in existing software. Students could use and refine the spreadsheet solutions to create a strategy for methodically testing software specifically for bias and equity.

Students identify how a given algorithm can be applied to real-world problems in different disciplines. For example, students could demonstrate how a randomization algorithm can be used to select participants for a clinical medical trial or to select a flash card to display on a vocabulary quiz. Alternatively, students could demonstrate how searching and sorting algorithms are needed to organize records in manufacturing settings, or to support doctors queries of patient records, or to help governments manage support services they provide to their citizens.

Many aspects of society, especially careers, have been affected by the degree of communication afforded by computing. The increased connectivity between people in different cultures and in different career fields has changed the nature and content of many careers. Students should explore different collaborative tools and methods used to solicit input from team members, classmates, and others, such as participation in online forums or local communities. For example, students could compare ways different social media tools could help a team become more cohesive.

Laws and ethics govern aspects of computing such as privacy, data, property, information, and identity. Students explain the beneficial and harmful effects of intellectual property laws as they relate to potential innovations and governance. For example, students could explain how patents protect inventions but may limit innovation. Alternatively, students could explain how intellectual property laws requiring that artists be paid for use of their media might limit the choice of songs developers can use in their computational artifacts.

Data can be collected and aggregated across millions of people, even when they are not actively engaging with or physically near the data collection devices. Students recognize automated and non-evident collection of information and the privacy concerns they raise for individuals. For example, students could explain the impact on an individual when a social media site's security settings allows for mining of account information even when the user is not online. Alternatively, students could discuss the impact on individuals of using surveillance video in a store to track customers. Additionally, students could discuss how road traffic can be monitored to change signals in real time to improve road efficiency without drivers being aware and discuss policies for retaining data that identifies drivers' cars and their behaviors.

Laws govern many aspects of computing, such as privacy, data, property, information, and identity. International differences in laws and ethics have implications for computing. Students make and justify claims about potential and/or actual privacy implications of policies, laws, or ethics and consider the associated tradeoffs, focusing on society and the economy. For example, students could explore the case of companies tracking online shopping behaviors in order to decide which products to target to consumers. Students could evaluate the ethical and legal dilemmas of collecting such data without consumer knowledge in order to profit companies. Alternatively, students could evaluate the implications of net neutrality laws on society's access to information and on the impacts to businesses of varying sizes.