Code Print

AP ML

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Learning Objective

Evaluate expressions that manipulate strings.

Essential Knowledge

String concatenation joins together two or more strings end-to-end to make a new string.

A substring is part of an existing string.

AP Computer Science Principles Exam Reference Sheet

Enduring Understanding

Programs can be used to process data, which allows users to discover information and create new knowledge.

Learning Objective

Extract information from data using a program.

Essential Knowledge

Programs can be used to process data to acquire information.

Tables, diagrams, text, and other visual tools can be used to communicate insight and knowledge gained from data.

Search tools are useful for efficiently finding information.

Data filtering systems are important tools for finding information and recognizing patterns in data.

Programs such as spreadsheets help efficiently organize and find trends in information.

Some processes that can be used to extract or modify information from data include the following:

• transforming every element of a data set, such as doubling every element in a list, or adding a parent’s email to every student record

• filtering a data set, such as keeping only the positive numbers from a list, or keeping only students who signed up for band from a record of all the students

• combining or comparing data in some way, such as adding up a list of numbers, or finding the student who has the highest GPA

Learning Objective

Explain how programs can be used to gain insight and knowledge from data. 

Essential Knowledge

Programs are used in an iterative and interactive way when processing information to allow users to gain insight and knowledge about data.

Programmers can use programs to filter and clean digital data, thereby gaining insight and knowledge.

Combining data sources, clustering data, and classifying data are parts of the process of using programs to gain insight and knowledge from data.

Insight and knowledge can be obtained from translating and transforming digitally represented information.

Patterns can emerge when data are transformed using programs.

Based on the Understanding by Design® (Wiggins and McTighe) model, the AP Computer Science Principles Course and Exam Description provides a clear and detailed description of the course requirements necessary for student success. The course is designed to be equivalent to a first-semester introductory college computing course. The major areas of study in the course are organized around big ideas that encompass ideas foundational to studying computer science.

The AP Computer Science Principles course framework is organized into five big ideas.

Computational Thinking Practices

The AP Computer Science Principles course framework included in the course and exam description outlines distinct skills from computational thinking practices that students should practice and develop throughout the year—skills that will help them learn to think and act like computer scientists. Emphasis is placed on creativity and collaboration as pedagogical strategies to be used to develop a diverse, appealing, and inclusive classroom environment.

This website is written by Mr. Cheng, a high school computer science teacher and adjunct professor. He can be reached at mcheng @ appinventor.net He is available for consulting and tutoring.

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Enduring Understanding

To find specific solutions to generalizable problems, programmers represent and organize data in multiple ways.

Learning Objective

Enduring Understanding

Developers create and innovate using an iterative design process that is userfocused, that incorporates implementation/feedback cycles, and that leaves ample room for experimentation and risk-taking.

Enduring Understanding

Programmers break down problems into smaller and more manageable pieces. By creating procedures and leveraging parameters, programmers generalize processes that can be reused. Procedures allow programmers to draw upon existing code that has already been tested, allowing them to write programs more quickly and with more confidence.

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Enduring Understanding

While computing innovations are typically designed to achieve a specific purpose, they may have unintended consequences.

Learning Objective

Starter Code

a21problem1.lua

Enduring Understanding

Developers create and innovate using an iterative design process that is userfocused, that incorporates implementation/feedback cycles, and that leaves ample room for experimentation and risk-taking.

Learning Objective

Describe the purpose of a computing innovation.

Essential Knowledge

The purpose of computing innovations is to solve problems or to pursue interests through creative expression.

An understanding of the purpose of a computing innovation provides developers with an improved ability to develop that computing innovation.

Learning Objective

Explain how a program or code segment functions.

Essential Knowledge

A program is a collection of program statements that performs a specific task when run by a computer. A program is often referred to as software.

A code segment is a collection of program statements that is part of a program.

A program needs to work for a variety of inputs and situations.

The behavior of a program is how a program functions during execution and is often described by how a user interacts with it.

A program can be described broadly by what it does, or in more detail by both what the program does and how the program statements accomplish this function.

Learning Objective

Identify input(s) to a program. 

Essential Knowledge

Program inputs are data sent to a computer for processing by a program. Input can come in a variety of forms, such as tactile, audio, visual, or text.

An event is associated with an action and supplies input data to a program.

Events can be generated when a key is pressed, a mouse is clicked, a program is started, or any other defined action occurs that affects the flow of execution.

Inputs usually affect the output produced by a program.

In event-driven programming, program statements are executed when triggered rather than through the sequential flow of control.

Input can come from a user or other programs

Learning Objective

Identify output(s) produced by a program.

Essential Knowledge

Program outputs are any data sent from a program to a device. Program output can come in a variety of forms, such as tactile, audio, visual, or text.

Program output is usually based on a program’s input or prior state (e.g., internal values).

Enduring Understanding

Programs can be used to process data, which allows users to discover information and create new knowledge.

Learning Objective

Describe what information can be extracted from data. 

Essential Knowledge

Information is the collection of facts and patterns extracted from data.

Data provide opportunities for identifying trends, making connections, and addressing problems.

Digitally processed data may show correlation between variables. A correlation found in data does not necessarily indicate that a causal relationship exists. Additional research is needed to understand the exact nature of the relationship.

Often, a single source does not contain the data needed to draw a conclusion. It may be necessary to combine data from a variety of sources to formulate a conclusion.

Learning Objective

Describe what information can be extracted from metadata.

Essential Knowledge

Metadata are data about data. For example, the piece of data may be an image, while the metadata may include the date of creation or the file size of the image.

Changes and deletions made to metadata do not change the primary data.

Metadata are used for finding, organizing, and managing information.

Metadata can increase the effective use of data or data sets by providing additional information.

Metadata allow data to be structured and organized.

Learning Objective

Identify the challenges associated with processing data.

Essential Knowledge

The ability to process data depends on the capabilities of the users and their tools.

Data sets pose challenges regardless of size, such as:

• the need to clean data

• incomplete data

• invalid data

• the need to combine data source

Depending on how data were collected, they may not be uniform. For example, if users enter data into an open field, the way they choose to abbreviate, spell, or capitalize something may vary from user to user.

Cleaning data is a process that makes the data uniform without changing their meaning (e.g., replacing all equivalent abbreviations, spellings, and capitalizations with the same word).

Problems of bias are often created by the type or source of data being collected. Bias is not eliminated by simply collecting more data.

The size of a data set affects the amount of information that can be extracted from it.

Large data sets are difficult to process using a single computer and may require parallel systems.

Scalability of systems is an important consideration when working with data sets, as the computational capacity of a system affects how data sets can be processed and stored.

Enduring Understanding

The way a computer represents data internally is different from the way the data are interpreted and displayed for the user. Programs are used to translate data into a representation more easily understood by people.

Learning Objective

Compare data compression algorithms to determine which is best in a particular context. 

Essential Knowledge

Data compression can reduce the size (number of bits) of transmitted or stored data.

Fewer bits does not necessarily mean less information.

The amount of size reduction from compression depends on both the amount of redundancy in the original data representation and the compression algorithm applied.

Lossless data compression algorithms can usually reduce the number of bits stored or transmitted while guaranteeing complete reconstruction of the original data.

Lossy data compression algorithms can significantly reduce the number of bits stored or transmitted but only allow reconstruction of an approximation of the original data.

Lossy data compression algorithms can usually reduce the number of bits stored or transmitted more than lossless compression algorithms.

In situations where quality or ability to reconstruct the original is maximally important, lossless compression algorithms are typically chosen.

In situations where minimizing data size or transmission time is maximally important, lossy compression algorithms are typically chosen.

Enduring Understanding

Programmers break down problems into smaller and more manageable pieces. By creating procedures and leveraging parameters, programmers generalize processes that can be reused. Procedures allow programmers to draw upon existing code that has already been tested, allowing them to write programs more quickly and with more confidence.

Learning Objective

For generating random values:

a. Write expressions to generate possible values.

b. Evaluate expressions to determine the possible results.

Essential Knowledge

The exam reference sheet provides

Text: RANDOM(a, b)

Block:

which generates and returns a random integer from a to b, inclusive. Each result is equally likely to occur. For example, RANDOM(1, 3) could return 1, 2, or 3.

Using random number generation in a program means each execution may produce a different result.

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Learning Objective

Compare multiple algorithms to determine if they yield the same side effect or result. 

Essential Knowledge

Algorithms can be written in different ways and still accomplish the same tasks.

Algorithms that appear similar can yield different side effects or results.

Some conditional statements can be written as equivalent Boolean expressions.

Some Boolean expressions can be written as equivalent conditional statements.

Different algorithms can be developed or used to solve the same problem.

Learning Objective

For algorithms:

a. Create algorithms.

b. Combine and modify existing algorithms.

Essential Knowledge

Algorithms can be created from an idea, by combining existing algorithms, or by modifying existing algorithms.

Knowledge of existing algorithms can help in constructing new ones. Some existing algorithms include:

• determining the maximum or minimum value of two or more numbers

• computing the sum or average of two or more numbers

• identifying if an integer is or is not evenly divisible by another integer

• determining a robot’s path through a maze

Using existing correct algorithms as building blocks for constructing another algorithm has benefits such as reducing development time, reducing testing, and simplifying the identification of errors.

Enduring Understanding

Programmers break down problems into smaller and more manageable pieces. By creating procedures and leveraging parameters, programmers generalize processes that can be reused. Procedures allow programmers to draw upon existing code that has already been tested, allowing them to write programs more quickly and with more confidence.

Learning Objective

Select appropriate libraries or existing code segments to use in creating new programs.

Essential Knowledge

A software library contains procedures that may be used in creating new programs.

Existing code segments can come from internal or external sources, such as libraries or previously written code.

The use of libraries simplifies the task of creating complex programs.

Application program interfaces (APIs) are specifications for how the procedures in a library behave and can be used.

Documentation for an API/library is necessary in understanding the behaviors provided by the API/library and how to use them.

Enduring Understanding

While computing innovations are typically designed to achieve a specific purpose, they may have unintended consequences.

Learning Objective

Explain how the use of computing can raise legal and ethical concerns. 

Essential Knowledge

Material created on a computer is the intellectual property of the creator or an organization.

Ease of access and distribution of digitized information raises intellectual property concerns regarding ownership, value, and use.

Measures should be taken to safeguard intellectual property.

The use of material created by someone else without permission and presented as one’s own is plagiarism and may have legal consequences.

Some examples of legal ways to use materials created by someone else include:

• Creative Commons—a public copyright license that enables the free distribution of an otherwise copyrighted work. This is used when the content creator wants to give others the right to share, use, and build upon the work they have created.

• open source—programs that are made freely available and may be redistributed and modified

• open access—online research output free of any and all restrictions on access and free of many restrictions on use, such as copyright or license restrictions

The use of material created by someone other than you should always be cited.

Creative Commons, open source, and open access have enabled broad access to digital information.

As with any technology or medium, using computing to harm individuals or groups of people raises legal and ethical concerns.

Computing can play a role in social and political issues, which in turn often raises legal and ethical concerns.

The digital divide raises ethical concerns around computing.

Computing innovations can raise legal and ethical concerns. Some examples of these include:

• the development of software that allows access to digital media downloads and streaming

• the development of algorithms that include bias

• § the existence of computing devices that collect and analyze data by continuously monitoring activities

Enduring Understanding

There exist problems that computers cannot solve, and even when a computer can solve a problem, it may not be able to do so in a reasonable amount of time.

Learning Objective

For determining the efficiency of an algorithm:

a. Explain the difference between algorithms that run in reasonable time and those that do not.

b. Identify situations where a heuristic solution may be more appropriate.

Essential Knowledge

A problem is a general description of a task that can (or cannot) be solved algorithmically. An instance of a problem also includes specific input. For example, sorting is a problem; sorting the list (2,3,1,7) is an instance of the problem.

A decision problem is a problem with a yes/no answer (e.g., is there a path from A to B?). An optimization problem is a problem with the goal of finding the “best” solution among many (e.g., what is the shortest path from A to B?).

Efficiency is an estimation of the amount of computational resources used by an algorithm. Efficiency is typically expressed as a function of the size of the input.

An algorithm’s efficiency is determined through formal or mathematical reasoning.

An algorithm’s efficiency can be informally measured by determining the number of times a statement or group of statements executes.

Different correct algorithms for the same problem can have different efficiencies.

Algorithms with a polynomial efficiency or slower (constant, linear, square, cube, etc.) are said to run in a reasonable amount of time. Algorithms with exponential or factorial efficiencies are examples of algorithms that run in an unreasonable amount of time.

Some problems cannot be solved in a reasonable amount of time because there is no efficient algorithm for solving them. In these cases, approximate solutions are sought.

A heuristic is an approach to a problem that produces a solution that is not guaranteed to be optimal but may be used when techniques that are guaranteed to always find an optimal solution are impractical.

Enduring Understanding

While computing innovations are typically designed to achieve a specific purpose, they may have unintended consequences.

Learning Objective

Describe issues that contribute to the digital divide

Essential Knowledge

Internet access varies between socioeconomic, geographic, and demographic characteristics, as well as between countries.

The “digital divide” refers to differing access to computing devices and the Internet, based on socioeconomic, geographic, or demographic characteristics.

The digital divide can affect both groups and individuals.

The digital divide raises issues of equity, access, and influence, both globally and locally

The digital divide is affected by the actions of individuals, organizations, and governments.

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Learning Objective

For binary search algorithms:

a. Determine the number of iterations required to find a value in a data set.

b. Explain the requirements necessary to complete a binary search.

Essential Knowledge

The binary search algorithm starts at the middle of a sorted data set of numbers and eliminates half of the data; this process repeat until the desired value is found or all elements have been eliminated.

Data must be in sorted order to use the binary search algorithm.

Binary search is often more efficient than sequential/linear search when applied to sorted data.

w22problem1.lua

-- define main function
function main()
    print("Names: ")
    print("Welcome to our Trivia Game")
    -- trivia dictionary
    trivia = {}

end

-- call main function
main()

Enduring Understanding

Programmers break down problems into smaller and more manageable pieces. By creating procedures and leveraging parameters, programmers generalize processes that can be reused. Procedures allow programmers to draw upon existing code that has already been tested, allowing them to write programs more quickly and with more confidence.

Learning Objective

For procedure calls:

a. Write statements to call procedures.

b. Determine the result or effect of a procedure call.

Essential Knowledge

A procedure is a named group of programming instructions that may have parameters and return values.

Procedures are referred to by different names, such as method or function, depending on the programming language.

Parameters are input variables of a procedure. Arguments specify the values of the parameters when a procedure is called.

A procedure call interrupts the sequential execution of statements, causing the program to execute the statements within the procedure before continuing. Once the last statement in the procedure (or a return statement) has executed, flow of control is returned to the point immediately following where the procedure was called.

The exam reference sheet provides procName(arg1, arg2, ...) as a way to call

Text:

PROCEDURE procName(parameter1, parameter2, ...)

{

<block of statements>

}

Block:

which takes zero or more arguments; arg1 is assigned to parameter1, arg2 is assigned to parameter2, and so on.

The exam reference sheet provides the procedure

Text:

DISPLAY(expression)

Block:

to display the value of expression, followed by a space.

The exam reference sheet provides the

Text:

RETURN(expression)

Block:

statement, which is used to return the flow of control to the point where the procedure was called and to return the value of expression.

The exam reference sheet provides

result <-- procName(arg1, arg2, ...)

to assign to result the "value of the procedure" being returned by calling.

Text:

PROCEDURE procName(parameter1, parameter2, ...)

{

<block of statements>

RETURN(expression)

}

Block:

The exam reference sheet provides procedure

Text:

INPUT()

Block:

which accepts a value from the user and returns the input value.

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Learning Objective

Express an algorithm that uses sequencing without using a programming language.

Essential Knowledge

An algorithm is a finite set of instructions that accomplish a specific task.

Beyond visual and textual programming languages, algorithms can be expressed in a variety of ways, such as natural language, diagrams, and pseudocode.

Algorithms executed by programs are implemented using programming languages.

Every algorithm can be constructed using combinations of sequencing, selection, and iteration.

Learning Objective

Represent a step-by-step algorithmic process using sequential code statements. 

Essential Knowledge

Sequencing is the application of each step of an algorithm in the order in which the code statements are given.

A code statement is a part of program code that expresses an action to be carried out.

An expression can consist of a value, a variable, an operator, or a procedure call that returns a value.

Expressions are evaluated to produce a single value

The evaluation of expressions follows a set order of operations defined by the programming language.

Sequential statements execute in the order they appear in the code segment.

Clarity and readability are important considerations when expressing an algorithm in a programming language.

Learning Objective

Evaluate expressions that use arithmetic operators.

Essential Knowledge

Arithmetic operators are part of most programming languages and include addition, subtraction, multiplication, division, and modulus operators.

The exam reference sheet provides a MOD b, which evaluates to the remainder when a is divided by b. Assume that a is an integer greater than or equal to 0 and b is an integer greater than 0. For example, 17 MOD 5 evaluates to 2.

The exam reference sheet provides the arithmetic operators +, -, *, /, and MOD. Text and Block:

• a + b

• a - b

• a * b

• a / b

These are used to perform arithmetic on a and b. For example, 17 / 5 evaluates to 3.4.

The order of operations used in mathematics applies when evaluating expressions. The MOD operator has the same precedence as the * and / operators.

Enduring Understanding

Developers create and innovate using an iterative design process that is userfocused, that incorporates implementation/feedback cycles, and that leaves ample room for experimentation and risk-taking.

Learning Objective

Develop a program using a development process. 

Essential Knowledge

A development process can be ordered and intentional, or exploratory in nature.

There are multiple development processes. The following phases are commonly used when developing a program:

§ investigating and reflecting

§ designing

§ prototyping § testing

A development process that is iterative requires refinement and revision based on feedback, testing, or reflection throughout the process. This may require revisiting earlier phases of the process.

A development process that is incremental is one that breaks the problem into smaller pieces and makes sure each piece works before adding it to the whole.

Learning Objective

Design a program and its user interface.

Essential Knowledge

The design of a program incorporates investigation to determine its requirements.

Investigation in a development process is useful for understanding and identifying the program constraints, as well as the concerns and interests of the people who will use the program.

Some ways investigation can be performed are as follows:

§ collecting data through surveys

§ user testing § interviews

§ direct observations

Program requirements describe how a program functions and may include a description of user interactions that a program must provide.

A program’s specification defines the requirements for the program.

In a development process, the design phase outlines how to accomplish a given program specification.

The design phase of a program may include:

• brainstorming

• planning and storyboarding

• organizing the program into modules and functional components

• creation of diagrams that represent the layouts of the user interface

Learning Objective

Describe the purpose of a code segment or program by writing documentation. 

Essential Knowledge

Program documentation is a written description of the function of a code segment, event, procedure, or program and how it was developed.

Comments are a form of program documentation written into the program to be read by people and do not affect how a program runs.

Programmers should document a program throughout its development.

Program documentation helps in developing and maintaining correct programs when working individually or in collaborative programming environments.

Not all programming environments support comments, so other methods of documentation may be required.

Learning Ojbective

Acknowledge code segments used from other sources. 

Essential Knowledge

It is important to acknowledge any code segments that were developed collaboratively or by another source.

Acknowledgement of a code segment(s) written by someone else and used in a program can be in the program documentation. The acknowledgement should include the origin or original author’s name.

Starter Code

print("Activity 2.2")

-- Example 1


-- Example 2 


-- Example 3

a22problem1.lua

-- Problem 1
print("Problem 1")

a22problem2.lua

a22problem3.lua

Starter Code

a24problem1.lua

-- Problem 1
print("Problem 1")

a24problem2.lua

a24problem3.lua

a24problem4.lua

a24problem5.lua

a24problem6.lua

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Enduring Understanding

To find specific solutions to generalizable problems, programmers represent and organize data in multiple ways.

Learning Objective

Enduring Understanding

The way a computer represents data internally is different from the way the data are interpreted and displayed for the user. Programs are used to translate data into a representation more easily understood by people.

Starter Code

w10problem1.lua

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Starter Code

w11problem1.lua

Enduring Understanding

Computer systems and networks facilitate the transfer of data.

Learning Objective

Enduring Understanding

There exist problems that computers cannot solve, and even when a computer can solve a problem, it may not be able to do so in a reasonable amount of time.

Learning Objective

Starter Code

s11problem1.lua

Source Code

w12problem1.lua

Starter Code

s10problem1.lua

Enduring Understanding

Parallel and distributed computing leverage multiple computers to more quickly solve complex problems or process large data sets.

Learning Objective

For sequential, parallel, and distributed computing:

a. Compare problem solutions.

b. Determine the efficiency of solutions.

Essential Knowledge

Sequential computing is a computational model in which operations are performed in order one at a time.

Parallel computing is a computational model where the program is broken into multiple smaller sequential computing operations, some of which are performed simultaneously

Distributed computing is a computational model in which multiple devices are used to run a program.

Comparing efficiency of solutions can be done by comparing the time it takes them to perform the same task.

A sequential solution takes as long as the sum of all of its steps.

A parallel computing solution takes as long as its sequential tasks plus the longest of its parallel tasks.

The “speedup” of a parallel solution is measured in the time it took to complete the task sequentially divided by the time it took to complete the task when done in parallel.

Learning Objective

Describe benefits and challenges of parallel and distributed computing. 

Essential Knowledge

Parallel computing consists of a parallel portion and a sequential portion.

Solutions that use parallel computing can scale more effectively than solutions that use sequential computing.

Distributed computing allows problems to be solved that could not be solved on a single computer because of either the processing time or storage needs involved.

Distributed computing allows much larger problems to be solved quicker than they could be solved using a single computer.

When increasing the use of parallel computing in a solution, the efficiency of the solution is still limited by the sequential portion. This means that at some point, adding parallel portions will no longer meaningfully increase efficiency

Enduring Understanding

Computer systems and networks facilitate the transfer of data.

Learning Objective

Explain how computing devices work together in a network.

Essential Knowledge

A computing device is a physical artifact that can run a program. Some examples include computers, tablets, servers, routers, and smart sensors.

A computing system is a group of computing devices and programs working together for a common purpose.

A computer network is a group of interconnected computing devices capable of sending or receiving data.

A computer network is a type of computing system.

A path between two computing devices on a computer network (a sender and a receiver) is a sequence of directly connected computing devices that begins at the sender and ends at the receiver.

Routing is the process of finding a path from sender to receiver.

The bandwidth of a computer network is the maximum amount of data that can be sent in a fixed amount of time.

Bandwidth is usually measured in bits per second.

Learning Objective

Explain how the Internet works.

Essential Knowledge

The Internet is a computer network consisting of interconnected networks that use standardized, open (nonproprietary) communication protocols.

Access to the Internet depends on the ability to connect a computing device to an Internet connected device.

A protocol is an agreed-upon set of rules that specify the behavior of a system.

The protocols used in the Internet are open, which allows users to easily connect additional computing devices to the Internet.

Routing on the Internet is usually dynamic; it is not specified in advance.

The scalability of a system is the capacity for the system to change in size and scale to meet new demands.

The Internet was designed to be scalable.

Learning Objective

Explain how data are sent through the Internet via packets

Essential Knowledge

Information is passed through the Internet as a data stream. Data streams contain chunks of data, which are encapsulated in packets.

Packets contain a chunk of data and metadata used for routing the packet between the origin and the destination on the Internet, as well as for data reassembly.

Packets may arrive at the destination in order, out of order, or not at all.

IP, TCP, and UDP are common protocols used on the Internet.

Learning Objective

Describe the differences between the Internet and the World Wide Web.

Essential Knowledge

The World Wide Web is a system of linked pages, programs, and files.

HTTP is a protocol used by the World Wide Web.

The World Wide Web uses the Internet

Enduring Understanding

While computing innovations are typically designed to achieve a specific purpose, they may have unintended consequences.

Learning Objective

Explain how people participate in problem-solving processes at scale.

Essential Knowledge

Widespread access to information and public data facilitates the identification of problems, development of solutions, and dissemination of results

Science has been affected by using distributed and “citizen science” to solve scientific problems.

Citizen science is scientific research conducted in whole or part by distributed individuals, many of whom may not be scientists, who contribute relevant data to research using their own computing devices.

Crowdsourcing is the practice of obtaining input or information from a large number of people via the Internet.

Human capabilities can be enhanced by collaboration via computing.

Crowdsourcing offers new models for collaboration, such as connecting businesses or social causes with funding.

Enduring Understanding

While computing innovations are typically designed to achieve a specific purpose, they may have unintended consequences.

Learning Objective

Explain how an effect of a computing innovation can be both beneficial and harmful.

Essential Knowledge

People create computing innovations.

The way people complete tasks often changes to incorporate new computing innovations.

Not every effect of a computing innovation is anticipated in advance.

A single effect can be viewed as both beneficial and harmful by different people, or even by the same person.

Advances in computing have generated and increased creativity in other fields, such as medicine, engineering, communications, and the arts.

Learning Objective

Explain how a computing innovation can have an impact beyond its intended purpose.

Essential Knowledge

Computing innovations can be used in ways that their creators had not originally intended:

§ The World Wide Web was originally intended only for rapid and easy exchange of information within the scientific community.

§ Targeted advertising is used to help businesses, but it can be misused at both individual and aggregate levels.

§ Machine learning and data mining have enabled innovation in medicine, business, and science, but information discovered in this way has also been used to discriminate against groups of individuals

Some of the ways computing innovations can be used may have a harmful impact on society, the economy, or culture.

Responsible programmers try to consider the unintended ways their computing innovations can be used and the potential beneficial and harmful effects of these new uses.

It is not possible for a programmer to consider all the ways a computing innovation can be used.

Computing innovations have often had unintended beneficial effects by leading to advances in other fields.

Rapid sharing of a program or running a program with a large number of users can result in significant impacts beyond the intended purpose or control of the programmer.

Source Code

w14problem1.lua

w14problem2.lua

w14problem3.lua

w14problem4.lua

w14problem5.lua

w14problem6.lua

w14problem7.lua

w14problem8.lua

w14problem9.lua

Source Code

w15problem1.lua

w15problem2.lua

w15problem3.lua

w15problem4.lua

w15problem5.lua

w15problem6.lua

w15problem7.lua

w15problem8.lua

w15problem9.lua

Starter Code

print("Activity 2.3")

-- Addition (+)


-- Subtraction (-)


-- Multiplication (*)


-- Division (/)


-- Integer Division (//)


-- Exponentiation (^)


-- Modulo (%)

a23problem1.lua

a23problem2.lua

a23problem3.lua

a23problem4.lua

Enduring Understanding

Programmers break down problems into smaller and more manageable pieces. By creating procedures and leveraging parameters, programmers generalize processes that can be reused. Procedures allow programmers to draw upon existing code that has already been tested, allowing them to write programs more quickly and with more confidence.

Source Code

w13problem1.lua

Starter Code

s12problem1.lua

Enduring Understanding

The way statements are sequenced and combined in a program determines the computed result. Programs incorporate iteration and selection constructs to represent repetition and make decisions to handle varied input values.

Learning Objective

For list operations:

a. Write expressions that use list indexing and list procedures.

b. Evaluate expressions that use list indexing and list procedures.

Essential Knowledge

The exam reference sheet provides basic operations on lists, including:

• accessing an element by index

Text:

aList[i]

Block:

accesses the element of aList at index i. The first element of aList is at index 1 and is accessed using the notation aList[1].

• assigning a value of an element of a list to a variable

Text:

x <-- aList[i]

Block:

• assigning a value to an element of a list

Text:

aList[i] <-- x

Block:

assigns the value of x to aList[i].

Text:

aList[i] <-- aList[j]

Block:

assigns the value of aList[j] to aList[i].

• inserting elements at a given index

Text:

INSERT(aList, i, value)

Block:

shifts to the right any values in aList at indices greater than or equal to i. The length of the list is increased by 1, and value is placed at index i in aList.

• adding elements to the end of the list

Text:

APPEND(aList, value)

Block:

evaluates to the number of elements currently in aList.

List procedures are implemented in accordance with the syntax rules of the programming language.

• removing elements

Text:

REMOVE(aList, value)

Block:

removes the item at index i in aList and shifts to the left any values at indices greater than i. The length of aList is decreased by 1.

• determining the length of a list

Text:

LENGTH(aList)

Block:

evaluates to the number of elements currently in aList.

List procedures are implemented in accordance with the syntax rules of the programming language.

Learning Objective

For algorithms involving elements of a list:

a. Write iteration statements to traverse a list.

b. Determine the result of an algorithm that includes list traversals.

Essential Knowledge

Traversing a list can be a complete traversal, where all elements in the list are accessed, or a partial traversal, where only a portion of elements are accessed.

Iteration statements can be used to traverse a list.

The exam reference sheet provides

Text:

FOR EACH item IN aList

{

<block of statements>

}

Block:

The variable item is assigned the value of each element of aList sequentially, in order, from the first element to the last element. The code in block of statements is executed once for each assignment of item.

Knowledge of existing algorithms that use iteration can help in constructing new algorithms. Some examples of existing algorithms that are often used with lists include:

• determining a minimum or maximum value in a list

• computing a sum or average of a list of numbers

Linear search or sequential search algorithms check each element of a list, in order, until the desired value is found or all elements in the list have been checked.

Enduring Understanding

The use of computing innovations may involve risks to personal safety and identity

Learning Objective

Source Code

w16problem1.lua

Source Code

w19problem1.lua

Source Code

w17problem1.lua

w17problem2.lua

w17problem3.lua

w17problem4.lua

w17problem5.lua

w17problem6.lua

w17problem7.lua

w17problem8.lua

w17problem9.lua

project2.lua

Source Code

w18problem1.lua

w18problem2.lua

w18problem3.lua

w18problem4.lua

w18problem5.lua

w18problem6.lua

playlist.lua

Part I

Enduring Understanding

Incorporating multiple perspectives through collaboration improves computing innovations as they are developed.