One of the most critical items in crafting in effective presentation is the proper visualization of supporting data.  A good picture will both engage the audience and highlight the salient features embedded within the data.  As a scientist, I have sat through numerous talks with poorly executed visualizations—tables overcrowded with numbers (most of which are irrelevant), plots containing too many overlapping and indistinguishable lines, indecipherable figures, etc…  The result of these was, almost uniformly, audiences who were uninterested and unwilling to believe the conclusions because they couldn’t understand any of the data being presented.  Even though there are plenty of examples of what not to do, sometimes it can be hard to find positive examples, especially for presenting the complex data or results that come out of business analysis.  While looking for ways to develop my visualization skills, I recently encountered this blog post: http://www.targetprocess.com/articles/visual-encoding.html, which has a few good rules-of-thumb for creating presentations:

• Humans do better comparing relative areas, so if you want to map data to a shape, you should map it to its area.
• Use no more than a dozen colors to encode categories effectively.  If there’s more, it becomes difficult to differentiate them.
• A diverging color scale should have different colors for positive and negative values.
• A planar chart is best for representing simple two variable data sets.

As an example of how good data visualization can help build a story and highlight underlying trends and relationships, here are, what I think, are two effective uses of a particular visualization type called a heat map.  In a heat map, data are plotted on a plane (usually projected onto an image of some particular area) and colored according to frequency or some other variable.  This representation helps quickly highlight where important areas (geographic or other) are on the map.

From The New York Times, a good visualization of basketball players shooting and scoring patterns: http://www.nytimes.com/interactive/2012/06/11/sports/basketball/nba-shot-analysis.html

And finally, a visualization of where all the action is on a typical World of Tanks game on the Abbey map: http://www.vbaddict.net/heatmaps/abbey/12