Altmetric started tracking attention to research across various attention sources in October 2011. The table below lists the dates when source coverage began and ended, if applicable. 


Coverage dates refer to when Altmetric set up tracking of each source. We may, however, hold historical data for certain sources. For example, in policy documents and citations we are often able to collect historical data.

  

Data source

Coverage began

Coverage ended*

Twitter

Oct 2011

-

Facebook

Oct 2011

-

Policy documents

Jan 2013

-

News

Oct 2011 &

Dec 2015**

-

Blogs

Oct 2011

-

Mendeley

Oct 2011

-

CiteULike

Oct 2011

Dec 2014

Post-publication peer reviews

Mar 2013

-

Reddit

Oct 2011

-

Wikipedia

Jan 2015

-

Stack Overflow

Oct 2011

-

Faculty of 1000 Prime

May 2013

-

Google+

Oct 2011

-

YouTube

Apr 2013

-

Sina Weibo

Mid-March 2014

7/24/2015

LinkedIn

Early 2013

3/12/2014

Pinterest

Oct 2011

6/20/2013

Open Syllabus 
 Sept 2016
 

Scopus citations

June 2016. Data goes as far back as 1823, although majority are post-1996

-

Web of Science citations
February 2017. Data is available only for institutional subscribers of products with Clarivate Analytics.

Patent citations        
April 2018

* "Coverage ended" means that we stopped collecting data on this date. All data previously aggregated will remain in our database and continue to appear in Altmetric details pages, Explorer, and the Altmetric API.

** We redeveloped our news tracking system and significantly improved coverage in December 2015: articles published after this date will have a higher number of news stories associated with them.