Abuses of Data

Many books have been written on the misrepresentations of Data: How to Lie with Statistics (Huff 1954), Damned Lies and Statistics and More Damned Lies and Statistics (Best 2004). These books serve to bring to light the many ways in which data has been misused to serve an agenda or a motive.  The purpose of this post is the identify, according to Dr. Bracey, some of the most common abuses of data.

Naive Failure to Do the Arithmetic

Consider the following quote, "Every year since 1950, the number of American children gunned down has doubled." (Bracey, 19) This quote seems harmless.  Yet, when we do the arithmetic, the author of this statement is claiming that in 2004, approximately 18,014,398,510,000,000,000 children were killed by guns.  Aside from misrepresenting information, this comment also lacks specifics that could make a difference. Bracey states that the following questions should be answered:

• How does the author define children?
• Where did he/she get the statistics?
• What does he/she mean by "gunned down?

Deliberate Distortions:

So often statistics are deliberately misused to misinform people in relation to accept the agenda of a given policy, point of view, or program.  One example given in the text is:

"In a Washington Post oped, former secretary of education William Bennet write, 'Nationally, about half of all high school graduates have not mastered seventh grade arithmetic.' (2000, A25) This statement lacks specificity, too.  We don't test high school graduates, so how could he know?" (Bracey, 23)

Selective Use of Statistics: Principle of Data Interpretation: When comparing groups, make sure the groups are comparable.

Considered by Bracey as the most common abuse of statistics the selective use of statistics, "reveal only part of the picture, the part supporting the author's agenda.  Recently, on 60 Minutes, there was a claim that we are living three years longer now than we did 100 years ago.  This study was completed by averaging the median age of mortality.  When we take the infant mortality rate and death of mothers during birthing of 100 years ago out of the equation, the mean changes from three to six years longer.  Are we really comparing apples to apples here?  The study should be further broken in to categories to give a more accurate portrayal.