Misconceptions About Statistics and Statistical Evidence

Abstract

Thanks in large part to advances in computing and information technology, statistics are everywhere. Whether the information concerns business, health, politics, sports, or nearly anything else, it is likely to appear in statistical form. The front page of the country’s highest circulation daily newspaper (USA Today) is littered with descriptive statistics and graphical depictions of those statistics. The star of a popular prime-time television show called Numbers solves fictional legal cases each week through the innovative use of statistics and statistical reasoning. And so, it is no surprise that statistics and statistical arguments find their way into the American courtroom at an unprecedented rate. Fienberg (1989 reported “dramatic growth” in the use of statistical evidence from the 1960s through the 1980s. He noted that the terms “statistic” or “statistical” appeared in thousands of reported district court opinions (p. 7). I performed a Westlaw search on these terms and found a 56% increase in the use of these terms in the Federal Cases database from 1990 to 2004. I also found that the phrase “statistical analysis” appeared 94% more often in 2004 than in 1990; “regression analysis” appeared 95% more often.