Wednesday, May 15, 2013

Graphs are Believable Right?

Interesting how easily someone can be deceived by political information or any information at that.  Most generally if someone is using numbers or graphs to most people it's believable. 
This was my job for many years at a hospital I worked at.  Collect data from different systems and combine all the info into really pretty believable graphs.  Very quickly I became what most people would call a "computer geek".  Or I was often called the "number lady". One thing about my job was to make sure it was totally accurate.  I ran at times hundreds of data reports to double check numbers with each system, Once all my data was collected and a graph supported the info I had to list all my sources and show the raw data.  I also know that very easily I could have manipulated any graph to look any way I wanted it to.  Easiest way would be to manipulate the numbers however if your showing your raw data and sources that can be a little tricky.  However just by changing your vertical value on a graph can change the total appearance of how you look at a graph.  It can either make columns smaller or larger even with the correct data which is very deceiving to the eye.  Most people do not read the small print on a graph.  Most generally they evaluate the picture. 

Here is a really good example of manipulation.


Several things are wrong with this graph.  One look at the vertical value it's in 50% increments which is very deceiving to the eye.  Second, it is labeled as percent increase in public debt. When in fact the data used is gross federal debt not public debt.  Third, each president served a different amount of terms and the percentage is a total for all the terms.  This chart was made in 2011 with Obama only having served a half of a term compared to the other presidents whom served several terms.  It does support that information under each column but again who's reading the small print.   Most importantly look at the source where the data came from, Office of the Democratic Leader and the year the data was collected.  Notice its not in enlarged print as the title Who Increased The Debt.  To most people there eyes are drawn to the large print and the pictures.

So now let's compare....
   Notice this graph is in 10% increments and is including different terms for each president rather than all together.  It also tells you that Obama's percentage is a projected amount.  Most importantly look at the sources.  There is more than one and they are not a one party source.

This is only one small example of how manipulating articles can be.  So next time when you see a pretty graph with pictures and big bold titles don't always believe.  Read the small print and research the sources if you are looking for accurate information.  This was my random thought for the evening after reading an article :-) 

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