Concept Check Answers

Concept Check # 1:
What is the difference between the Internet and the World Wide Web?

The Internet is the tangible structure consisting of computers linked to computers by cables. The World Wide Web is the abstract information shared by the computers and consists of documents, videos, pictures, etc.

Concept Check # 2:
Give an example to explain the difference between a website and a webpage. is a website with thousands of personal webpages made by its users. When you type into the URL bar of your browser, you get the homepage of Myspace (which is also a webpage). When you log-in, your are viewing your personal webpage within the website.

Concept Check # 3:
If you knew nothing of IBM, Intel, or Johnny, how would you decide their importance to users based on the picture?

IBM and Intel reserve their recommendations, and are most likely great sources to find other quality webpages, but Johnny might recommend any page since not many pages recommend him, but he links to many others.

Concept Check # 4:
Give a summary of PageRank and the idea behind Google.

Before Google, search engines depended on context and frequency of use to recommend pages for a search. However, Google uses PageRank and context to rank the pages for a user. PageRank works like bibliometrics for papers. Pages with many in-links have a higher rank than pages with fewer in-links. Also, a hyperlink from page A with a high ranking counts for more in the ranking of page B than a hyperlink from page C with a low ranking.

Concept Check # 5:
Find the second iteration PageRank of each page in Figure 1.

Concept Check # 6:
Write out the matrix multiplication of equation (3) to show that it is the same as the summation equation (2).

Concept Check # 7:
What does fixing the cycles mean for the graph in Figure 3?

This means adding a hyperlink from every page to every other page.

Concept Check # 8:
What would it mean to make α = 0.60?

Since G = (S + (1-α)(1/n)eeT, &alph; = 0.60 that 60% of the time, the surfer will use hyperlinks, while 40% of the time, the surfer will type the address into the URL bar.

Activity 00309-05:

[Letter] [Activity 00309-01] [Internet History]
[Wikiracing] [PageRank] [Mathematics] [Playing] [Test]

[Glossary] [Back To Top] [Alphabetical Glossary] [Contact Author]

This material is based upon work supported by National Science Foundation under Grant No. 0546622.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the
author and do not necessarily reflect the views of the National Science Foundation.