Often a report must be able to be grouped by one or more categories, depending on the user's requirements.
Sometimes, across groups, it's helpful to highlight common elements. Imagine that the illustration below lists employees by department (the main grouping), with the last column being a common element to all employees:

It's difficult to identify common elements across the main group for the last column in figure 1, even though values like "AAAAA" and "ZZZZZ" are repeated. In fact, it's not possible to draw any conclusions about the last column (like how many employees share the common element "ZZZZZ") without physically scanning the entire text of the last column. It would be easier to visualise if the last column was in its own sub-group - although doing so would interrupt the flow of the main group, department.
Here's a revised illustration where the only change is color to the last column:

From the revised illustration in figure 2, it's easy to see how many "ZZZZZ" employees there are (highlighted in oceanic aqua), and even the fact that there's some in both sets, without really having to read the text.
Color is being used here as a "Pre-Attentive Variable": something that may convey information to a user, before they've paid attention to it. Next week, in part 2 of "Enhancing Visualisation of Common Elements Across Groups Using Color in Reporting Services 2005", I'll demonstrate the code to color Reporting Services table cells without hardcoding the variables, so my technique is re-useable between reports.
Tags: reporting services, visual, group, color
posted @ Tuesday, March 10, 2009 1:09 PM