Week 2

Our study of search indexing from last unit continues into the other main aspect of search with this unit's Algorithm of the Week: ranking. From here on out, we will be exploring two programming chapters per unit, so in addition to the chapter you read last unit to prepare, there is a mid-unit checkpoint for reading another programming chapter; this week we will explore putting numbers and text in Python programs. Additionally, we will explore the famous “ones and zeros” that modern computing is built on.

This unit's written assignment has a new kind of prompt. As we explore various algorithms and the technologies they power, it is important to consider the effects of these new technologies. Read Impacts of Computing in Welcome to CS to learn about a framework we will be using to explore the human effects—the affects—of computing. You will be asked to read an article online about a computational technology and to analyze its impacts for yourself. At the end of the Impacts of Computing chapter are samples of what we are looking for. These impacts questions will reappear every other unit.

Upon finishing this learning module, you should be able to:

  • Describe the difference between analog and digital
  • Use units of information such as bits, bytes, and multiplier prefixes
  • Convert between binary and decimal numeral systems
  • Explain how the PageRank algorithm works
  • Write Python code to do simple computation with numbers and strings
  • Weigh the benefits and harms of a technology as it affects humans

Binary and Bits

Read Binary and Bits in Welcome to CS. Continue through the first three sections of Data Representation (stop when you reach Binary Addition).

Explore the Binary Practice worksheet. Worksheets like this are provided so you can practice the material and verify that you understand it before doing the written assignment. You will not turn the worksheets in. Do the problems and use the key to check your own work. If you have questions about any of the problems on a worksheet, ask about them!

Algorithm of the Week: PageRank

Read Chapter 3 of Nine Algorithms that Changed the Future. Try out a PageRank simulator to get a feel for the algorithm; the simulator will also come in handy for the worksheet and written assignment.

Explore the the PageRank Practice worksheet. It has a few problems you can use to test your understanding of how link structure influences ranking. You can check your work with the key.

Program or be Programmed

What does it mean not to know how programming works in the modern world?

How Google Search Works

Learn some more details about how pages get ranked.