Article Level Metrics (ALMs) "provide a picture of how an individual article is being discussed, shared, and used" .
Altmetrics vs. Article-Level Metrics
"As adoption of Article-Level Metrics has increased, the term “Altmetrics” is sometimes used interchangeably with ALMs. It’s important to distinguish between two similar - but not synonymous - terms. ALMs are an attempt to measure impact at the article level. In doing so, ALMs draw from a variety of different data sources, some traditional (e.g., times cited) and some new (e.g., tweets). The attempt to incorporate new data sources to measure the impact of something, whether that something is an article or a journal or an individual scholar, is what defines altmetrics. Altmetrics are about the data sources, not the level of aggregation. ALMs are about the incorporation of altmetrics and traditional data points to define impact at the article level."
As a user you will typically see Article-Level Metrics displayed on journal pages or in specialized web applications. You can sign up with your Mozilla Persona account if you want direct access to the underlying data - this will give you an API key for API access and will alert you when the monthly summary stats are available for download. The online documentation gives detailed instructions on how data from external sources are collected.
PLOS Article-Level Metrics (ALM) Reports provides a comprehensive report of article-level metrics for articles published in PLOS journals. You choose which articles to include and this tool will create a report with metrics data and visualizations that you can download, save and share. Please note this this tool is only for articles published in PLOS journals.
Here are some of the metrics included in an ALM Report:
Number of page views and downloads from PLOS and PubMed Central
Times cited from CrossRef, PubMed Central and Scopus
Saves to CiteULike and Mendeley
Mentions on NatureBlogs, Twitter, Facebook and Wikipedia