Sometimes statistics and data can be manipulated by not placing the numbers in context.  Check out this short video about graphs and context for some aspects to consider.

Being able to evaluate statistical information is important, as statistics can be manipulated so that they tell the story that the person using them wants to tell. We have all heard how it is possible to “lie” with statistics. 

However, evaluating statistical information can be a very difficult task, and in some cases is something that only experts or others with advanced knowledge of statistics know how to do, as it requires an in-depth understanding of the data-gathering process and the mathematical techniques used to generate the statistics. [This is something you’d learn a bit about in an introductory statistics class, which is a really good idea to take at some point, as this is very useful information!]

Nonetheless, with some common sense, everyone can learn to be wary and critical of the numbers they find and can hopefully avoid being “duped” by statistics. 

Here are a few general points to keep in mind when working with statistical information: 

• Who collected the data? Do they have a particular interest in the results?
• Do the statistics show any bias? 
• Are the data timely? Check the time period when the data were collected.
• Is the coverage complete? What was the population, or sample size, of the study? For example, the sample size of the decennial U.S. Census of Population and Housing is theoretically the total number of people in the United States. The sample size for a most other studies, surveys, and polls will be much smaller. 
• Has the data been “re-packaged”? For example, government data published by a private source might not be as complete.
• Is the data from a primary source? If it is from a secondary source (for example, the Statistical Abstract), has it been properly documented so that you can find the primary source?