A01 chaf6542 06 se fm indd

,

headings denoted within HTML), occur-

rence in 

link anchor text

, proximity, frequency or density and position in document.

Spiders or robots

Spiders are software 

processes, technically 

known as robots, 

employed by search 

engines to index web 

pages of registered sites 

on a regular basis.

Link anchor text

The text used to form the 

blue underlined hyperlink 

viewed in a web browser 

defined in the HTML 

source.

Figure 9.9

Stages in producing natural search engine listings

Phase 1

Determine relevant

document set.

Rank in order of 

relevance

Search query

string

User searches

Query/Rank

processes

SERPs

Phase 2

Extract document

titles and snippets.

Return as SERPS

Crawl

control

Crawlers

Inverted 

index servers

Document and

link history

Crawl/Index

processes

The WWW

web pages and

documents/media

Inverted 

index servers

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Chapter 9  Customer relationship management

3 

Ranking or scoring. The indexing process has produced a lookup of all the pages that 

contain particular words in a query, but they are not sorted in terms of relevance. Ranking 

of the document to assess the most relevant set of documents to return in the SERPs 

(search engine results pages, Figure 9.10) occurs in real time for the search query entered. 

First, relevant documents will be retrieved from a  run-  time version of the index at a par-

ticular data centre, then a rank in the SERPs for each document will be computed based 

on many ranking factors of which we highlight the main ones in later sections.