Termometer depicts the change of the frequency of word across a corpus spread over time. It provides a more compact version of the tool TermsRadio. Unlike TermsRadio the temporal dimension of the tool is not expanded across the x-axis. Instead the change in frequency of the word is captured in through movement in the y-axis.

Getting Started

When you first arrive to the TermsRadio tool you will see one of two possible screens:

termometer-without-corpus termometer-with-corpus

Termometer without a pre-loaded corpus. See loading texts into Voyeur for help on how to proceed.

Termometer with a pre-loaded corpus. You were probably given a URL that included the corpus, or you’re viewing a page that has an embedded Voyeur tool in it. If you prefer, you can also start without a corpus.

Interface Elements

Termometer includes the standard set of interface elements (see image below). For more help with these see the Voyeur Tools Standard Interface Elements page.

Standard UI Elements

Reading the tool

The main body of the tool depicts words moving up and down. This movement is indicating the change in the word’s frequency trend across the corpus. For words that are selected this is further accentuated by a flare that provides a trace of the words trend in the segments that have already passed. Below the graph body is the “Navigation bar”, this area displays the line graph for the selected words over the entire corpus. If no words are selected the area will be blank. The default for both the graph body and the “Navigation bar” is for the y-axis to be scaled logarithmically.

Upon loading Termometer will begin scrolling through the segments of the corpus. This movement can be controlled by a number of features on the lower toolbar. These features are fairly self-evident, “Stop” will pause the scrolling, “Resume” will un-pause the scrolling and “Restart” will return the tool to the beginning of the corpus.


The tool is provided with a fisheye hover effect. When the mouse tip is over an area of the graph body the words will become slightly splayed and the font will become more opaque. This will be even more apparent when the scrolling is stopped, as the fish eye effect will move with the speed of the mouses movement and not necessarily with the speed of the scrolling animation.

Adding and removing words

While all the words are present in the graph body as data points, a flare indicating their frequency trend is not present unless the user selects the word. A word can be selected by clicking on the word in the graph body. To deselect a word click the word once again in the graph body.
While the mouse pointer is hovering over a word it will be selected similarly to clicking on the word. A line in red will appear in the the “Navigation bar” indicating the word’s frequency trend. However as soon as the mouse pointer is moved off of the word it is deselected. Hovering over a word will not add a flare to the graph body.

Important options

Within the options panel Termometer allows for the user to toggle between a logarithmic scale and a linear scale for the y-axis. The default setting for Termometer is for the y-axis to be scaled logarithmically.


Linking from the tool

Double clicking on one of the words in the graph body will open a new instance of Voyant Tools with a focus on that word.


Like all Voyeur tools, Termometer can be reused in a variety of ways:

  • create a link that is specific to the corpus and options that are currently being used
  • embed the current corpus and options as a tool in an external page

For more information see exporting and reusing Voyeur Tools.