Simplest forms of Search Engine Optimisation

First generation engines relied heavily on tf/idf

• The top-ranked pages for the query maui resort were the ones containing the most mauis and resorts

SEOs - dense repetitions of chosen terms

• e.g., maui resort maui resort maui resort
• Often, the repetitions would be in the same color as the background of the web page
  • Repeated terms got indexed by crawlers
  • But not visible to humans on browsers

Note: tf/idf is term frequency divided by inverse document frequency, so a frequent word gets a high value unless the word is common in the whole document collection.