Citations of tweets.

*<p>Total citations (1063) greater than total number of tweets (917) because some messages contained both internal and external citations and are represented more than once.</p

Actual and Predicted Informative Tweets.

<p>Actual and Predicted Informative Tweets.</p

Relationships between numbers of tweets and citations.

<p>Relationships between numbers of tweets and citations.</p

Distribution of tweet citations.

<p>Distribution of tweet citations.</p

Tweets from Kidney Week 2011.

<p>Tweets from Kidney Week 2011.</p

Distribution of sentiment scores.

<p>Distribution of sentiment scores.</p

Relationship between numbers of tweets and tweeters.

<p>Relationship between numbers of tweets and tweeters.</p

Distribution of tweet content.

<p>Distribution of tweet content.</p

Overall video quality based on user engagement and video duration.

<p>^a Excludes one video.</p><p>^b Represents videos containing 4 or more educational domains.</p><p>% or greater).^c Represents videos with a raw SAM score of 27 or greater (70</p><p>^d Represents videos containing b and c.</p

Pareto plot of educational domains present in YouTube videos.

<p>Pareto plot of educational domains present in YouTube videos.</p