Search the California Content Standards

Standard:
Explain that the amount of space required to store data differs based on the type of data and/or level of detail.

Descriptive Statement:
All saved data requires space to store it, whether locally or not (e.g., on the cloud). Music, images, video, and text require different amounts of storage. Video will often require more storage and different format than music or images alone because video combines both. The level of detail represented by that data also affects storage requirements. For instance, two pictures of the same object can require different amounts of storage based upon their resolution, and a high-resolution photo could require more storage than a low-resolution video. Students select appropriate storage for their data. For example, students could create an image using a standard drawing app. They could save the image in different formats (e.g., .png, .jpg, .pdf) and compare file sizes. They should also notice that different file sizes can result in differences in quality or resolution (e.g., some pictures could be more pixelated while some could be sharper). Alternatively, in an unplugged activity, students could represent images by coloring in squares within a large grid. They could model how a larger grid requires more storage but also represents a clearer image (i.e., higher resolution).

Standard:
Create clearly named variables that store data, and perform operations on their contents.

Descriptive Statement:
A variable is a container for data, and the name used for accessing the variable is called the identifier. Students declare, initialize, and update variables for storing different types of program data (e.g., text, integers) using names and naming conventions (e.g. camel case) that clearly convey the purpose of the variable, facilitate debugging, and improve readability. For example, students could program a quiz game with a score variable (e.g. quizScore) that is initially set to zero and increases by increments of one each time the user answers a quiz question correctly and decreases by increments of one each time a user answers a quiz question incorrectly, resulting in a score that is either a positive or negative integer. (CA CCSS for Mathematics 6.NS.5) Alternatively, students could write a program that prompts the user for their name, stores the user's response in a variable (e.g. userName), and uses this variable to greet the user by name.

Standard:
Design and iteratively develop programs that combine control structures and use compound conditions.

Descriptive Statement:
Control structures can be combined in many ways. Nested loops are loops placed within loops, and nested conditionals allow the result of one conditional to lead to another. Compound conditions combine two or more conditions in a logical relationship (e.g., using AND, OR, and NOT). Students appropriately use control structures to perform repetitive and selection tasks. For example, when programming an interactive story, students could use a compound conditional within a loop to unlock a door only if a character has a key AND is touching the door. (CA CCSS for ELA/Literacy W.6.3, W.7.3, W.8.3) Alternatively, students could use compound conditionals when writing a program to test whether two points lie along the line defined by a particular linear function. (CA CCSS for Mathematics 8.EE.7) Additionally, students could use nested loops to program a character to do the "chicken dance" by opening and closing the beak, flapping the wings, shaking the hips, and clapping four times each; this dance "chorus" is then repeated several times in its entirety.

Standard:
Decompose problems and subproblems into parts to facilitate the design, implementation, and review of programs.

Descriptive Statement:
Decomposition facilitates program development by allowing students to focus on one piece at a time (e.g., getting input from the user, processing the data, and displaying the result to the user). Decomposition also enables different students to work on different parts at the same time. Students break down (decompose) problems into subproblems, which can be further broken down to smaller parts. Students could create an arcade game, with a title screen, a game screen, and a win/lose screen with an option to play the game again. To do this, students need to identify subproblems that accompany each screen (e.g., selecting an avatar goes in the title screen, events for controlling character action and scoring goes in the game screen, and displaying final and high score and asking whether to play again goes in the win/lose screen). Alternatively, students could decompose the problem of calculating and displaying class grades. Subproblems might include: accept input for students grades on various assignments, check for invalid grade entries, calculate per assignment averages, calculate per student averages, and display histograms of student scores for each assignment. (CA CCSS for Mathematics 6.RP.3c, 6.SP.4, 6.SP.5)

Standard:
Create procedures with parameters to organize code and make it easier to reuse.

Descriptive Statement:
Procedures support modularity in developing programs. Parameters can provide greater flexibility, reusability, and efficient use of resources. Students create procedures and/or functions that are used multiple times within a program to repeat groups of instructions. They generalize the procedures and/or functions by defining parameters that generate different outputs for a wide range of inputs. For example, students could create a procedure to draw a circle which involves many instructions, but all of them can be invoked with one instruction, such as “drawCircle.” By adding a radius parameter, students can easily draw circles of different sizes. (CA CCSS for Mathematics 7.G.4) Alternatively, calculating the area of a regular polygon requires multiple steps. Students could write a function that accepts the number and length of the sides as parameters and then calculates the area of the polygon. This function can then be re-used inside any program to calculate the area of a regular polygon. (CA CCSS for Mathematics 6.G.1)

Standard:
Design a project that combines hardware and software components to collect and exchange data.

Descriptive Statement:
Collecting and exchanging data involves input, output, storage, and processing. When possible, students select the components for their project designs by considering tradeoffs between factors such as functionality, cost, size, speed, accessibility, and aesthetics. Students do not need to implement their project design in order to meet this standard. For example, students could design a mobile tour app that displays information relevant to specific locations when the device is nearby or when the user selects a virtual stop on the tour. They select appropriate components, such as GPS or cellular-based geolocation tools, textual input, and speech recognition, to use in their project design. Alternatively, students could design a project that uses a sensor to collect the salinity, moisture, and temperature of soil. They may select a sensor that connects wirelessly through a Bluetooth connection because it supports greater mobility, or they could instead select a physical USB connection that does not require a separate power source. (CA NGSS: MS-ETS1-1, MS-ETS1-2)

Standard:
Represent data in multiple ways.

Descriptive Statement:
Computers store data as sequences of 0s and 1s (bits). Software translates to and from this low-level representation to higher levels that are understandable by people. Furthermore, higher level data can be represented in multiple ways, such as the digital display of a color and its corresponding numeric RGB value, or a bar graph, a pie chart, and table representation of the same data in a spreadsheet. For example, students could use a color picker to explore the correspondence between the digital display or name of a color (high-level representations) and its RGB value or hex code (low-level representation). Alternatively, students could translate a word (high-level representation) into Morse code or its corresponding sequence of ASCII codes (low-level representation).

Standard:
Create more generalized computational solutions using collections instead of repeatedly using simple variables.

Descriptive Statement:
Computers can automate repetitive tasks with algorithms that use collections to simplify and generalize computational problems. Students identify common features in multiple segments of code and substitute a single segment that uses collections (i.e., arrays, sets, lists) to account for the differences. For example, students could take a program that inputs students' scores into multiple variables and modify it to read these scores into a single array of scores. Alternatively, instead of writing one procedure to find averages of student scores and another to find averages of student absences, students could write a single general average procedure to support both tasks.

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).