Elastic search takes all our data, cleans it (such as stemming and HTML stripping), and then puts it into an inverted index where content is separated and organized.
The search uses 3 fields:
Title
Keywords
_all
The _all field is essentially a very large string made out of an item’s inverted index (such as non-module widget content, documents, and module items).
You "hit" on this data based on occurrence and relevancy metrics.
It also searches titles and keywords, and if those "hit," it carries more weight (see Boosts) than hitting on the ALL string.
Search Result Weights
The only thing that receives a weighted factor (or a boost) in search results are Keywords. The rest of the results are based on the frequency of the search term.
If you would like to add a weighted factor to the Title or other additional fields, please read how to Configure Boost Fields Search.
The search tool looks at everything in a long string and calculates how many times a term is referenced in content areas, descriptions, and widgets. If a term is also in a title or keywords then it shows higher in the results.
Boosts:
Title = 0 By Default
Keywords = 1.5
Decayed modules:
Activities
Agenda Center
AlertCenter
Archive
Bids
Blog
Calendar
CityPolls
CivicAlerts (News Flash)
Community Voice
MediaCenter
Photo Gallery
Real Estate Locator
Note:
Pages do not decay
We use an exponential decay
We are at:
"Scale": "21d"
"Offset": "21d"
"Decay": 0.9
Decays use different dates in the modules
Calendar decays on Event Date, Agenda Center on Meeting Date
Decay Date
Items in Document Center, Pages, Facilities, Form Center, Forms, Staff Directory, FAQs, and Notify Me do not have a decay date. We believe it would hinder the search results if we said after x amount of time, this expires from showing in results. The reason is that it is quite possible that a document from 2010 is still the most accurate and relevant item that a site user needs. So, the date is not a factor for search results in regard to the modules mentioned earlier.