Unit 4 - Big Data and Privacy

The data rich world we live in also introduces many complex questions related to public policy, law, ethics and societal impact. In many ways this unit acts as a unit on current events. It is highly likely that there will be something related to big data, privacy and security going on in the news at any point in time. The major goals of the unit are 1) for students to develop a well-rounded and balanced view about data in the world around them and both the positive and negative effects of it and 2) to understand the basics of how and why modern encryption works.

Chapter 1: The World of Big Data and Encryption

Big Questions

  • What opportunities do large data sets provide for solving problems and creating knowledge?
  • How is cybersecurity impacting the ever-increasing number of Internet users?
  • How does cryptography work?

Enduring Understandings

  • 3.2 Computing facilitates exploration and the discovery of connections in information.
  • 3.3 There are trade offs when representing information as digital data.
  • 4.2 Algorithms can solve many but not all computational problems.
  • 6.3 Cybersecurity is an important concern for the Internet and the systems built on it.
  • 7.1 Computing enhances communication, interaction, and cognition.
  • 7.3 Computing has a global affect -- both beneficial and harmful -- on people and society.
  • 7.4 Computing innovations influence and are influenced by the economic, social, and cultural contexts in which they are designed and used.

Week 1

Lesson 1: What is Big Data?

Students are introduced to the concept of “big data,” where it comes from, what makes it “big,” and how people use big data to solve problems, and how much of their lives are “datafied” or could be.

Teacher Links: Video Student Links: Activity Guide |

Lesson 2: Rapid Research - Data Innovations

Students "rapidly research" a topic of personal interest and respond to questions about how that innovation produces, uses, or consumes data.

Teacher Links: Answer Key Student Links: Video | Video | Video | Activity Guide | |

Lesson 3: Identifying People With Data

Students investigate some of the world’s biggest data breaches to get a sense for how frequently data breaches happen what kinds of data is lost or stolen.

Teacher Links: Answer Key Student Links: | Web Site | Web Site | Activity Guide

Week 2

Lesson 4: The Cost of Free

Students examine some of the economic concerns and consumer tradeoffs related to apps and websites that collect and track data about you in exchange for providing you a service free of cost.

Teacher Links: Exemplar Student Links: Video | Article | External Article | Activity Guide |

Lesson 5: Simple Encryption

Students are introduced to encryption and use a widget to attempt cracking Caesar and random substitution ciphers.

Student Links: Widget | Widget |

Week 3

Lesson 6: Encryption with Keys and Passwords

Students use a widget to experiment with the Vigenère cipher to learn about the relationship between cryptographic keys and passwords.

Teacher Links: Answer Key | Answer Key Student Links: Worksheet | Widget | Worksheet | Code Studio Page | Video | Resource |

Optional Lesson: Hard Problems - Traveling Salesperson Problem


Students examine a well-known computationally hard 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.

Teacher Links: Student Links: Worksheet

Optional Lesson: One-way Functions - The WiFi Hotspot Problem


Students explore another computationally hard problem - the “Wireless Hotspot Problem” (also know as the vertex cover or dominating sets problem) - to investigate the characteristics of a "one-way function": a problem which is easy to construct in such a way that you know the solution, but is computationally hard to solve.

Teacher Links: Answer Key | Answer Key | Student Links: Worksheet | Worksheet

Lesson 7: Public Key Cryptography

In this big, multi-step lesson, students learn how the basic mechanics and underlying mathematical principles of public key encryption work. Public key encryption is the basis for most secure transactions on the internet.

Teacher Links: Answer Key | Teacher Guide | Teacher Guide | Teacher Demonstration Guide Student Links: Activity Guide | Activity Guide | Code Studio | Video | Handout | Resource

Lesson 8: Rapid Research - Cybercrime


Students pick a type of cyber attack or cybercrime and do some “rapid research” to learn more about it. The lesson is a precursor to the Practice Performance Task about Big Data and Security.

Teacher Links: Answer Key Student Links: Video Worksheet | Web Resource | Video | Activity Guide

Week 4

Lesson 9: Practice PT - Big Data and Cybersecurity Dilemmas

Students complete a small research project about a dilemma related to either Big Data or Cybersecurity. The project mimics elements of the Explore Performance Task.

Student Links: Practice PT |

Chapter Commentary

Unit 4 Chapter 1 - What’s the story?

The story of this chapter is about coming to terms with the world of Big Data that we now inhabit, and addressing the new modern dilemmas that come along with it. In many ways, this unit acts as a current events unit, since the daily news is filled with examples: should the government get “backdoor keys” to encryption algorithms in order to unlock a cell phone used by a terrorist? Should a social media site be able to use the data it has about you and your relationships to direct advertising at you, or sell information about you to others? At the end of the unit, students are asked to develop an opinion supported by their own research about a dilemma related to either cybersecurity or personal privacy.

There are two main threads in this unit, which are interwoven: (1) Big Data and (2) Encryption/Security. Since it is nearly impossible to talk about big data without delving into the issues related to security and privacy, it’s a useful time to learn about encryption and how it works. Encryption can be an engrossing subject in its own right, since it involves interesting algorithms, mathematics, and problem solving, not to mention the aspects of societal impact. Indeed, there are entire undergraduate degrees on the subject - The main goal of our encryption lessons is to work up to understanding how public key encryption works, including the primary mathematical principles that make it possible for two people (or computers) to send encrypted messages to each other over the internet in a way that only the intended recipient can decrypt it.

Ready for the Explore PT?

We think that the end of this unit represents a minimum point at which students could complete a successful Explore performance task. Check out the Performance Task pacing section on page 32 for more details.

Our Approach to the Content

Many of the lessons in this unit are designed as practice for elements of the Explore Performance Task. In particular, lesson 2 “Rapid Research” is good practice for the relatively quick research and writing students will have to do for the Explore PT. The goal is for students to become adept with looking up sources, reading/skimming articles for their main points, and being able to explain both sides of an argument or dilemma related to big data, security and privacy. Since issues about personal privacy and security affect students’ daily lives, the research should be relevant and engaging for students.

Most of the activities in these first two weeks call for students to be engaged in online research, to use online tools to investigate issues, as well as to discuss and write about the issues. These lessons in particular are a great entry point for the teacher to assume the role of lead learner. The first week in the unit will feel like: big data is great! The second week, however, might feel like: big data is scary! Especially in the latter case, the teacher might need to attend to their students’ runaway paranoia about the harmful effects of big data. We want to present a balanced view, but it is a dilemma! Big data is both great and scary at times. Knowledge and awareness are the best tools to protect yourself.

The activities in the third week around data encryption should look and feel similar to lessons from Units 1 and 2. The general pattern is to introduce a concept through an unplugged activity or thinking prompt, and then “plug it in” by using a widget to explore the concept further. The purpose of the widgets is to allow students time to play with some of the encryption ideas, which are often mathematical in nature, to get sense for how they work. We want to give students space to be curious and use the tools to experiment, explore and discover some essential properties of encryption.

We encourage teachers to use the practice PT to dry-run some of the procedures and processes for the Explore Performance Task. In particular: put time constraints on the research and writing, grant students latitude to research what they want, monitor the appropriateness of students’ research choices, and help them get “unstuck,” or push them to be more specific, by appealing to the scoring guidelines and rubric.