Note: Although my examples uses politics, this post is not for or against any candidate, party, platform, interest group, or any position in that nature.
The following is one of the most profound points that stuck with me from the statistics classes I’ve taken. Because of the amount of statistics available, it is easy to take a position and then find the numbers to support the position.
Graphs are visual representations of data. No matter if they are bars, points, lines, pies, scatter, area, picture, etc … they show the relationship between variables – usually two. Because visual representations help make a point, the graph maker can make decisions to best illustrate their point for the audience.
Several months ago, President Obama’s campaign used a graph similar to this regarding job growth. In my opinion, this was an effective graph to use because it visual delivered the message the campaign team desired. (Note: The campaign also showed 2008 decline in numbers that the graph to the right does not show – and no, I did not break my own rule about a political statement.)
Just as the campaign rightly and accurately displayed those numbers, the campaign stopped showing the commercial when the most recent numbers changed the trend line.
Graphs only display limited information – and in most cases – the two variables that the graph maker decides to display. This also means there is more to the story; just as the graph from Money magazine shows – which is something I know I stated here sometime in the past, but I just don’t know when.
Bottom line: Tread lightly on numbers because (assuming they are correct), they show one aspect of reality – especially if the numbers are coming from any politician or political entity. Don’t take their numbers for granted, thus examine it yourself.