Article

Page Rank

computer-science web-technologies algorithms

Calculation

The PageRank formula refines itself over time, considering current page scores.

Factors

  • In-bound links
    • Main factor, most effectual in PageRank
  • Frequency and magnitude of updates
  • Metadata and page elements
    • Keywords (metadata)
    • Descriptions (metadata)
    • H1 (elements)
  • Domain name
  • Site security (SSL certificate)
  • Page load times

Formula

Info

This does not need to be remembered.

PR(A)=(1−d)+d(PR(Ti)/C(Ti)+...+PR(Tn)/C(Tn)))PR(A) = (1-d) + d(PR(Ti)/C(Ti) + ... + PR(Tn)/C(Tn)))

PageRank score defaults to 1.

d - damping factor; prevents websites from getting an extreme score (< 1).

Typically 0.85.

C(page) = outbound links Ti = first page Tn = other page

Simple Example

PageRank Simple Example

Initial Page A Calculation

PR(A)=(1−0.85)+0.85(1/1)=1.0PR(A) = (1 - 0.85) + 0.85(1/1) = 1.0

Initial Page B Calculation

PR(B)=(1−0.85)+0.85(1.0/1)=1.0PR(B) = (1 - 0.85) + 0.85(1.0/1) = 1.0

Page A Re-calculation

PR(A)=(1−0.85)+0.85(1.0/1)=1.0PR(A) = (1 - 0.85) + 0.85(1.0/1) = 1.0