Yet another fallacy.
This fallacy is committed when a person places unwarranted confidence in drawing a conclusion from statistics that are unknown.
- “Unknown” statistical data D is presented.
- Conclusion C is drawn from D with greater confidence than D warrants.
Unknown statistical data is just that, statistical data that is unknown. This data is different from “data” that is simply made up because it has at least some foundation.
One common type of unknown statistical data is when educated guesses are made based on limited available data. For example, when experts estimate the number of people who use illegal drugs, they are making an educated guess. As another example, when the number of total deaths in the Iraqi war is reported, it is (at best) an educated guess because no one knows for sure how many people have been killed.
Another common type of unknown statistical date is when the data can only be gathered in ways that are likely to result in incomplete or inaccurate data. For example, statistical data about the number of people who have affairs is likely to be mostly in this category.
Obviously, unknown statistical data is not very good data. However, drawing an inference from such data is not, in itself, an error. In some cases, such inferences can be quite reasonable.
For example, while the exact number of people killed in the Iraq war is unknown, it is reasonable to infer from the data that many people have died. As another example, while the exact number of people who do not pay their taxes is unknown, it is reasonable to infer that the government is losing some revenue because of this.
The error that makes this a fallacy is to place too much confidence in a conclusion drawn from such unknown data. Or, to be a bit more technical, to overestimate the strength of the argument based on statistical data that is not adequately known.
This is an error because, obviously enough, a conclusion is being drawn that is not adequately justified by the premises.
Naturally, the way in which the statistical data is gathered also needs to be assessed to determine whether or not other errors have occurred.
“Several American Muslims are known to be terrorists or at least terrorist supporters. As such, I estimate that there are hundreds of actual and thousands of potential Muslim-American terrorists. Based on this, I am certain that we are in grave danger from this large number of enemies within our own borders.”
“Experts estimate that there are about 11 million illegal immigrants in the United States. While some people are not worried about this, consider the fact that the experts estimate that illegals make up about 5% of the total work force. This definitely explains that percentage of American unemployment since these illegals are certainly stealing 5% of America’s jobs.”
Sally: “I just read an article about cheating.”
Jane: “How to do it?”
Sally: “No! It was about the number of men who cheat.”
Sasha: “So, what did it say?”
Sally: “Well, the author estimated that 40% of men cheat.”
Kelly: “Hmm, there are five of us here.”
Janet: “You know what that means…”
Sally: “Yes, two of our boyfriends are cheating on us. I always thought Bill and Sam had that look…”
Janet: “Hey! Bill would never cheat on me! I bet it is your man-he is always given me the eye!”
Sally: ‘What! I’ll kill him!”
Janet: “Calm down. I was just kidding. I mean, how can they know that 40% of men cheat? I’m sure none of the boys are cheating on us. Well, except maybe Sally’s man.”