The History of heat maps

Timelines, Visualization


For my timeline, I chose to create a history of the heat map. From some of the readings we have done for class I realized there are several different ways to visualize information and decided to focus on exploring one type. While this timeline is a brief overview, a viewer can use the five points I’ve included as a guide to research more on the topic of heat maps.

A few questions that I asked at the start of this project were:

  • When was the heat map first used?
  • Who developed it?
  • Who uses heat maps most frequently?
  • What kinds of heat maps are there?
  • What other visualizations were already being used?


I used Google Sheets to collect and organize my data as well the sources I used. I also searched Google Images for imagery and linked directly to each photo that was used. I used Wikipedia as a starting point for my research to link to academic publications and for personal biographies of some people included in the timeline. I used Pratt’s Library site to look up certain academic articles I came across in my research. This information was then uploaded to TimelineJS. TimelineJS is the open-source program I used for the information visualization.

A link to my timeline can be found here:

A link to my Google Sheet with the data can be found here:


Because I had never done any research on heat maps before this, I wanted to create a general overview of the history of heat maps. My searches included styles of heat maps, key developers of heat maps, the history of heat maps, and popular uses for heat maps. While I wasn’t able to find an example of every heat map, I was able to find some popular ones. When reading articles, I checked their bibliographies for related articles. I tried to include not only styles of heat maps, but also people who were involved with the development of heat maps.


My resulting timeline has five data points with imagery and thumbnails. Three points show different types of heat maps: A treemap, a mosaic plot, and a density function visualization. The other two parts show the man who trademarked the term “heat map” and the first heat map ever created.


I wish I had more time to do a more comprehensive background search. I would have liked to do some more research in academic databases in order to see how people were using heat maps in their reports and to see if different schools of thought tended to use one type of heat map over another, such as biologists using heat maps to depict different types of gene expressions.

I believe that, with more time, this timeline could have been built out more and included more data points as well as more comprehensive information on heat maps. For example, I did not touch on how heat maps are often used in meteorology or how epidemiologists have used heat maps to show outbreak locations. I provided minimal information for each point but would have felt more comfortable providing more information if I had had more time to verify the different information I came across.

While I appreciate the ease of open-source software, I would have also liked a bit more control on how the timeline was constructed. I liked that I could link to both GIFs and photos; however, I wish I could have more say in how the photos were displayed in relation to the actual timeline at the bottom and the text.