Instructions: Check boxes below to choose which lines to display on the graph. The three vertices denote the first half of 2010, the second half of 2010, and the first quarter of 2011. These time periods have an about equal number of tweets. The y-axis displays percentage of tweets containing the selected term from the corresponding time period. Checking the first checkbox of a group displays all the terms that belong to that category, including the combined statistics, which can be compared individually by checking the overall checkboxes.