A heat map is a graphical representation of data where the values taken by a variable in a two-dimensional map are represented as colors. A very similar presentation form is a tree map. The term is also used to mean its thematic application as a choropleth map.
Heat maps originated in 2D displays of the values in a data matrix. Larger values were represented by small dark gray or black squares (pixels) and smaller values by lighter squares. Sneath (1957) displayed the results of a cluster analysis by permuting the rows and the columns of
a matrix to place similar values near each other according to the clustering. Jacques Bertin used a similar representation to display data that conformed to a Guttman scale. The idea for joining cluster trees to the rows and columns of the data matrix originated with Robert Ling in 1973. Ling used overstruck printer characters to represent different shades of gray, one character-width per pixel. Leland Wilkinson developed the first computer program in 1994 (SYSTAT) to produce cluster heat maps with high-resolution color graphics. The Eisen et al. display shown in the figure is a replication of the earlier SYSTAT design.
There are several different kinds of heat map:
- Web heat maps have been used for displaying areas of a Web page most frequently scanned by visitors.
- Biology heat maps are typically used in molecular biology to represent the level of expression of many genes across a number of comparable samples (e.g. cells in different states, samples from different patients) as they are obtained from DNA microarrays.
- The tree map is a 2D hierarchical partitioning of data that visually resembles a heat map.
A mosaic plot is a tiled heat map for representing a two-way or higher-way table of data. As with treemaps, the rectangular regions in a mosaic plot are hierarchically organized. The means that the regions are rectangles instead of squares. Friendly (1994) surveys the history and usage of this graph.
Ref.Wiki
So What’s a Heat Map and how it is useful for Web marketing?
Through years of research in web marketing, patterns have been seen in the ways that people not only navigate the web, but web sites and even web pages. All of this data was compiled by marketing firms and used to create a heat map.
Heat maps are charts that show us where most people look when they open a web site or page, by human instinct. The map displays regions colored yellow, orange and red – the darker the color, the more high-profile the spot is.
So if you are a web analyst/developer: simply look at a heat map before you design your next web site, plan to remodel your existing one, or are planning on remodeling your online advertising campaign, and make sure the ads are placed in the right “hot” areas!
Website Heat Maps
A heat map enables the website owner to determine what areas of a website the visitors find most interesting. It is best displayed visually.
Heat map image of Google
As you can see the more red the color, the greater the activity on that area of the website. Thus, for Google rankings the top 5 listings get a majority of the eye balls. You will also notice the red lines on the image, these represent the “fold,” the area above where you would have to scroll down to see more of the page.
Website Heat Maps with eye tracking
An eyetracking “heatmap” shows how much users looked at different parts of a Web page. Areas where users looked the most are colored red; the yellow areas indicate fewer fixations, followed by the least-viewed blue areas. Gray areas didn’t attract any fixations.
