The purpose of this question is to ferret out sloppiness or bias in the research process as opposed to bias in the researcher herself. The researcher is likely to discover that her sampling is both crime and fart-free, not necessarily because this finding is accurate but because few people will look a stranger in the eye and admit either to committing a crime of to performing a socially stigmatized act. Perhaps the most common methodological mistake is to rely upon an unrepresentative sampling. In order to predict which candidate would win the 1936 presidential election, millions of people were polled, using phone calls and subscription lists of the magazine. Of course, Roosevelt won.
Many calculations are useless without knowing their context.
At that point, the surprising stat is that twenty-five percent preferred lemonade. Whenever you note that a small group of people have been surveyed, your suspicions should be roused, and not only because of the statistical insignificance of the sampling. It is quite possible, and perhaps quite common for some researchers to conduct a multitude of small surveys until one of them produces the desired results. On the basis of this survey, he concluded that a tossed penny come up heads eighty percent of the time. This conclusion is not justified, however, because the increased reporting may reflect nothing more than a greater willingness on the part of women to contact the police or a greater willingness on the part of police to file the reports.