This is the third of three lessons that make the connection between programming and algorithms. In this lesson students continue to work with the "Human Machine Language" to get creative designing more algorithms for playing cards. One command is added to the language from the previous lesson (SWAP) that allows positions of cards to change. With the addition of swap the challenge is to design an algorithm that will move the minimum card to the front of the list while keeping the relative order of all the other cards the same. If that is achieved some other Human Machine Language challenges are available.

This lesson is a student's first exposure to programming in App Lab. The lesson begins with a quick reflection prompt. Then students are introduced to the practice of pair programming before beginning to program. For this lesson the students' view is limited to only a very few simple “turtle” commands to draw graphics on the screen. After a few warm up exercises, using only combinations of four drawing commands, students must figure out the most “efficient” way to draw an image of a 3x3 grid. The lesson concludes with a sense-making discussion about the meaning of efficiency in programming and the reason behind beginning with such a limited set of programming tools.

In this lesson, students learn to define and call procedures (in JavaScript, procedures are called “functions”) in order to create and give a name to a group of commands for easy and repeated use in their code. They will be introduced to functions as a form of abstraction that enables them to write code in larger, more logical chunks and focus on what something does, rather than how it does it. As they explore the use of functions through a sequence of activities in App Lab, they will be asked to think about where they see the need for functions and how these functions can make their code clearer or more concise.

At the end of the lesson students review the concept of abstraction and are introduced to elements of the Create PT in preparation for the Practice PT at the end of the unit.

This lesson presents a top-down problem-solving strategy for designing solutions to programming problems. Students use a worksheet to learn about top-down design, and then on paper, design a solution to a new turtle drawing challenge with a partner. Having practiced this approach on paper and in code, students will be re-presented with the 3x3 square challenge from an earlier lesson and asked to improve upon their old solution by designing multiple layers of functions.

Students will learn to read App Lab’s API documentation and will use functions that accept parameters in order to complete a series of drawing puzzles which require them to make use of the App Lab API documentation to learn new drawing commands. Many of these commands will require the use of parameters. The final challenge asks students to design a personal monogram making use of the commands they learned during the lesson.

In this lesson, students practice using and creating functions with parameters. Students learn that writing functions with parameters can generalize solutions to problems even further. Especially in situations where feel like you are about to duplicate some code with only a few changes to some numbers, that is a good time to write a function that accepts parameters. In the second half of the lesson, students make a series of modifications to a program that creates an “Under the Sea” scene by adding parameters to functions to more easily add variation to the scene. Lastly, students are introduced to App Lab’s random number functions to supply random values to function calls so the scene looks a little different every time the program runs.

Students learn to use random values and looping to create variation in their drawings and quickly duplicate objects they wish to appear in their digital scenes many times. Students will be presented with a version of the for loop which only enables them to change the number of times the loop runs. This block is essentially a "repeat" block and will be presented that way. Students will also be presented with blocks which enable them to choose a random number within a given range. Together these blocks enable students to create more complex backgrounds for digital scenes by randomly placing simple objects within the background of their scene. Students use these tools to step through the Under the Sea exemplar digital scene.

To conclude their study of big data and cryptography, students will complete a small research project related to a dilemma presented by Big Data or Cybersecurity, in the form of a Practice Performance Task. Students will pick one of two issues to research more deeply - either an issue related to big data, or one related to cybersecurity. Students will need to identify appropriate online resources to learn about the functionality, context, and impact of the technological innovation that gave rise to the dilemma they are investigating. After completing their research, students will present their findings both in a written summary and with an audio / visual artifact they found online. The written components students must complete are similar to those students will see in the AP Performance Tasks.

This project is an opportunity to practice many of the skills students will use when completing the Explore Performance Task on the AP® Exam at the end of the year. While an open-ended research project might be intimidating, students have built all the skills they need to complete this task.

**Note:** This is NOT the official AP® Performance Task that will be submitted as part of the Advanced Placement exam; it is a practice activity intended to prepare students for some portions of their individual performance at a later time.

**Note for 2017-18 School Year:** This Practice PT has NOT been updated to reflect changes to the [Explore PT Scoring Guidelines](https://apcentral.collegeboard.org/pdf/2018-explore-performance-tasks-sg.pdf) released in Fall 2017. We recommend you review those guidelines to understand the similarities between this project and the actual Explore PT.

Students learn about various types of cybercrimes and the cybersecurity measures that can help prevent them. Then students perform a Rapid Research project investigating a particular cybercrime event with a particular focus on the data that was lost or stolen and the concerns that arise as a result. The Rapid Research activity features vocabulary, concepts, and skills that should help prepare them for the AP Explore PT, and also serves as a capstone for the sequence of lessons on encryption and security.

In this lesson, students are introduced to the concept of “[v big data],” where it comes from, what makes it “big,” and how people use big data to solve problems. Students are asked to consider how much of their lives are “datafied” or could be, and the teacher will show the projected growth of data in the world. Students will then investigate a big data tool in pairs to evaluate the tool for its usefulness and investigate the source of the data used to make the tool. A key take-away from the lesson is that different considerations need to be made when trying to look at, use, or analyze tools that use big data. The world of big data is big, and we’ve only begun to figure out how to solve problems with it.

The lesson concludes with a brief introduction to the AP Explore Performance Task which students are recommended to complete at the end of the unit.

Students use the Google Trends tool in order to visualize historical search data. They will need to identify interesting trends or patterns in their findings and will attempt to explain those trends, based on their own experience or through further research online. Afterwards, students will present their findings to ensure they are correctly identifying patterns in a visualization and are providing plausible explanations of those patterns.

This lesson asks students to consider carefully the assumptions they make when interpreting data and data visualizations. The class begins by examining how the Google Flu Trends project tried and failed to use search trends to predict flu outbreaks. They will then read a report on the Digital Divide which highlights how access to technology differs widely by personal characteristics like race and income. This report challenges a widespread assumption that data collected online is representative of the population at large. To practice identifying assumptions in data analysis, students are provided a series of scenarios in which data-driven decisions are made based on flawed assumptions. They will need to identify the assumptions being made (most notably those related to the digital divide) and explain why these assumptions lead to incorrect conclusions.

In this lesson students will conduct a small amount of research to explore a computing innovation that leverages the use of data. Students will research a topic of personal interest and respond to questions about about how that innovation produces, uses, or consumes data. The lesson is intended to give students practice with doing research of this nature and provides a small amount of scaffolding to help students figure out what to look for.

This lesson is intended to be a quick, short version of a performance task in which students rapidly do some research and respond in writing. It might take 2 class days but should not take more. The goal is to generate ideas for exploration later when students complete the actual Explore PT later in the year.

Students begin this lesson by investigating some of the world’s biggest data breaches to get a sense for how frequently data breaches happen within companies and organizations, and what kinds of data and information is lost or given up. Afterwards, students will use the Data Privacy Lab tool to investigate just how easily they could be uniquely identified with a few seemingly innocuous pieces of information. At the conclusion of the lesson, students will research themselves online to determine just how much someone could learn about them by conducting the same searches and “connecting the dots.”

This lesson focuses on the economic and consumer concerns around apps and websites that collect and track data about you in exchange for providing you a service free of cost. Often the quality of the service itself is dependent on having access to data about many people and their behavior. The main take-away of the lesson is that students should be more informed consumers of the technology around them. They should be able to explain some of the tradeoffs between maintaining personal privacy and using innovative software free of cost.

In this lesson, students are introduced to the need for encryption and simple techniques for breaking (or cracking) secret messages. Students try their own hand at cracking a message encoded with the classic Caesar cipher and also a Random Substitution Cipher. Students should become well-acquainted with idea that in an age of powerful computational tools, techniques of encryption will need to be more sophisticated. The most important aspect of this lesson is to understand how and why encryption plays a role in all of our lives every day on the Internet, and that making good encryption is not trivial. Students will get their feet wet with understanding the considerations that must go into making strong encryption in the face of powerful computational tools that can be used to crack it. The need for secrecy when sending bits over the Internet is important for anyone using the Internet.

In this lesson, students examine a classic problem in computer science, the Traveling Salesperson Problem (TSP). Students solve small instances of the problem, try to formulate algorithms to solve it, and discuss why these algorithms take a long time for computers (and humans) to compute. Students see how the TSP grows in size much faster than the problem of adding characters to a password. Even though we use encryption to motivate a desire to learn about computationally hard problems, they are valuable to know about, in and of themselves. This lesson covers some territory about how we reason formally and mathematically about algorithms and figuring out how “hard” something is for a computer to do.

In this lesson, students continue their exploration of computationally hard problems as they investigate a one-way function, a problem which is easy to construct in such a way that you know the solution, but it is computationally hard to solve. Students will begin the lesson by trying to solve the “Wireless Hotspot Problem” (also know as the vertex cover or dominating sets problem) to experience first-hand the challenge of solving it. They will then be instructed on how easy it is to create such a problem and will practice doing so themselves. In the Wrap-up, students are introduced to the concept of a one-way function and consider why such problems might be useful tools when constructing methods of encryption. If it’s easy to create a problem that is hard for a computer (or human!) to solve, then perhaps it is possible to make truly secure encryptions.

In this lesson, students learn about the relationship between cryptographic keys and passwords. Students explore the Vigenère cipher with a widget to examine how a cryptographic "key" can be used to encrypt and decrypt a message. Then, students use a tool that shows them about how long it would take to crack a given password using a standard desktop computer. Students experiment with what makes a good password and answer questions about the “human components” of cybersecurity.

This is a big multi-part lesson that introduces the concept of public key cryptography which is an answer to the crucial question: *How can two people send encrypted messages back and forth over insecure channels (the Internet) without meeting ahead of time to agree on a secret key?* In a nutshell, there are two main principles we want students to understand:

1. The mechanics of communication with public key cryptography
2. The basic mathematical principles that make it possible

The lesson gets at these two core ideas through a deliberate chain of thought experiments, demonstrations, activities and widgets. All parts are building blocks that lead to deeper understanding of how it works.