Analytics Magazine Analytics Magazine, July/August 2014 | Page 42

REAL - T IME T E X T A NA LY T I C S Figure 3: Trends stream graph. Incoming tweets over a time period were captured in a stream graph visualization as shown in the Figure 3 screenshot. Each topic is represented by a stream in the visualization and is characterized by the top words in that topic. At any point of time, the top words in each topic are displayed in a topic treemap below the stream graph. It is possible to get the keyword “treemap” at any past time in history. Successive runs of the sentiment analysis algorithm for batches of tweets are represented by the visual in Figure 4. Each bar captures the sentiment for that feature in a particular batch of tweets. The height of the bar represents the number of opinion words 42 | A N A LY T I C S - M A G A Z I N E . O R G for the feature in that batch. The color of each bar represents the overall sentiment level expressed in a batch of data, ranging from extremely negative (dark red) to extremely positive (dark green). The change in color of the bars across various batches can be used to identify stimuli that are driving the change. Selection of a particular bar provides a deeper analysis of that batch. The size of a bubble indicates the number of references of a particular opinion word, and the color shows the overall sentiment score for the particular opinion word. Both the size and color are indicators of which opinion words drive the sentiment for a feature in a batch. W W W. I N F O R M S . O R G