Presenting data is a very difficult challenge. The first step is engaging the audience with a strong emphasis on why it is important for them to understand what is being presented. Nevertheless they do need to be able to understand the data you present. While ensuring its relevance is understood is vital, so is it vital that your audience understand each and every piece of data that you present, or they will just as surely switch off, and your outcome is lost.  
Visuals are very useful here. Use pie graphs and bar charts; insert them into your slides if you are using slides. If you are using a whiteboard, draw as you tell the story or make the point. If you are using PREZi you can let the audience look at the data from different angles. The visual representation will reinforce your explanation and the point you are making.
If it is necessary to use graphs, diagrams and charts, make sure they are as simple as possible. While you probably want to impress with your understanding of complicated data, being able to simplify it will have far more of an impact, particularly in terms of getting your message across.
And make sure that everything about those visuals is clear. Sometimes it’s necessary to explain so that all the implications are clear as well. There may have been a very good reason for choosing the axes in the graph. There may have been a very good reason for choosing the increments that are used. While it may seem obvious to you, it may not be to the audience, and it may make the data relationships clearer.   
You can also add to the impact of the visuals. There may be a story behind the points on a graph. It is the intersection of two values and maybe the relationship is reasonably clear. But if you can give the reason why this relationship exists or maybe the history behind it, then it will be so much clearer.  And if you can put a human face on it, with a human story then the relationship and the point you are using it for will have so much more impact. If wages are going down and costs of living rising, for example,  then a story about a family forced to live in a car will make the impact so much more real. Another way to add a human face, or a realistic face, is to use a graphic representing the actual item being quantified. This can be particularly useful in a bar graph. If the bar consists of pictures of dollar coins to represent money, or of groups of people to represent populations or groups, for example, again the impact is multiplied.  
In the midst of all this, it is important to remember, still, that you are presenting points towards a persuasion of some kind. It can be useful to have the point you are making as the heading for the slide that contains the visuals.
And while the visuals should be as detailed as is necessary to make them understandable, too much detail will overwhelm. Remember the visuals only need to make a point, not necessarily present all the data. If all the data is necessary for later inspection and verification, put it in a handout, and leave the slides as simple as they can be.
Visuals are your greatest ally in presenting data. They can add impact and keep your audience engaged with the thread of your message. Your simplification and design of the material to support that message and the thoughtful explanation you add to it, will support the success of your data presentation.
©2012 Bronwyn Ritchie
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Bronwyn Ritchie has 30 years’ experience speaking to audiences and training in public speaking – from those too nervous to say their own name in front of an audience to community groups to corporate executives. To receive her fortnightly free tips, articles, quotations and resources, subscribe now, it’s free!. Visit http://www.pivotalpublicspeaking.com/ps_ezine.htm