Name: Facebook – shares, comments, and likes
Can apply to: All scholarly products that have a URL, including journal articles, books, web pages, blog posts, videos, and other products.
Metric definition: Likes, comments, and shares are direct actions that can be taken on Facebook posts. These functions are also integrated into other sites through social media widgets.
Metric calculation: A share is counted when a Facebook user shares a Facebook post with his or her Facebook friends, possibly adding commentary. A comment is counted when a user remarks upon a post. Likes are calculated based on the number of likes and shares for a URL, likes and comments on Facebook stories about the URL, and inbox messages containing the URL as an attachment.
Data sources: Altmetric, PlumX.
Appropriate use cases: Interactions on Facebook can be an indicator of general public interest and engagement, or engagement with a particular community.
Limitations: Altmetrics aggregators like Altmetric can only see and count public shares of your scholarly products. Such counts are more accurate if the DOI (Digital Object Identifier) for the product is included. When a Facebook user shares your work in a private message, it is not visible to these aggregators. Facebook counts should not be used as measures of quality or impact.
Inappropriate use cases: The correlation between Facebook shares, comments, and likes is weak and should not be used as a leading indicator of citations.
Available metric sources: Aggregators including Altmetric.com, PlumX, ImpactStory
Transparency: The transparency of Facebook shares, comments, and likes depends on the source. Some sources are completely transparent and allow you to view the specific interactions and users that generated the counts.
Timeframe: Facebook was publicly launched in February, 2004.