History of Computers - PageRank
Introduction
PageRank is Google's algorithm for deciding which web pages are the most relevant to the searched term.[1] It was created in 1996 by Larry Page. [2]
Overview
A page is assigned a high score if it has a lot of links from pages that are also highly-scored. A page’s score is a fractional one between 0 and 1, its PageRank. All of the scores in the Web must add up to 1. For our purposes, consider a Web that contains three pages: X, Y, and Z. X links to Y and Z, Y links to Z, and Z links back to X, as illustrated below. Initially, each page's’ score is ⅓. In each round of scoring, a page divides its previous score up and gives an equal share to each site that it links to. Thus, after the second round of scoring, X has a score of 1/3 because it divides its previous ⅓ and gives it to X and Z and receives all of Z’s previous ⅓ because it is its only link, Y has a score of ⅙ because it receives ⅙ of X’s previous ⅓, and Z has a score of ½ because it receives ⅓ from Y and ⅙ from X, totalling to ½. Eventually, after many rounds of scoring, the pages’ scores will begin to approach ⅖ for X, ⅖ for Z, and ⅕ for Y. These values that they approach serve as their scores.[4]
Significance
Before PageRank, search engines were based off of the content of the web pages and were not very good because they were not organized well. Without PageRank, the basis for Google, the internet as we know it may not be the same, as Google has influenced the evolution of the internet in a gigantic way. Without search engines such as Google, the internet would not be nearly as popular.
References
- ↑ How Computers Work Tenth Edition pages 195-196 by Ron White
- ↑ *http://www.google.com/corporate/history.html
- ↑ http://googlewavecommunity.com/wp-content/uploads/2014/10/Google-New-Search-Engine
- ↑ The Joy of X pages 191 - 198 by Steven Strogatz
- ↑ http://i.imgur.com/FUhpLD0
-Sebastian Varma Svarma (talk) 20:36, 14 September 2015 (CDT)
