“The annual accidental death toll for handgunrelated incidents is slightly under 200” Type of Accident or Manner of Injury 1996 Firearm Missile, E922 1,134 Handgun 187 Shotgun (automatic) 93 Hunting rifle 50 Other and unspecified firearms missile 804 Actual handgun total is 187 + some unknown fraction of the 804, likely much more than 200. Offenders Sentenced in U.S. District Courts under the U.S. Sentencing Commission guidelines (fiscal year 1999) Primary offense Total cases Total 55,388 Sexual abuse 230 bIncludes Race: Otherb Number Percent 2,189 4.0% 159 69.4% Native Americans, Alaska Natives, Asians, and Pacific Islanders. The The statistics are limited to 230 explanation: is pretty few sexual abuse cases for the federal cases, and whole country, isn’tthe it? federal government very rarely prosecutes sexual abuse (which is mostly U.S. District Courts – just what courts are a state law crime) – except on Indian those? reservations. Find 1. 2. Did 3. 4. 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Study: 15% of N.Y. drivers 16-25 drive drunk at least once a month. Minnesota commentator: 15% of driving-age teenagers drive drunk at least once a month. 1. Generalizing across places and times—make clear that the numbers refer to the N.Y. study, at the time the study was done. 2. Inferring from group’s behavior to a subset’s behavior—do teenage drivers (16-18 or 16-19) behave the same way as 18/19-25-year-olds? 3. Misreporting the study—the study focused on fraction of drivers who drive drunk, not on fraction of teenagers who drive drunk. [Article:] a handgun is six times more likely to be used to kill a friend or relative than to repel a burglar [A:] a handgun brought into the home for the purposes of selfprotection is six times more likely to kill a relative or acquaintance than to repel a burglar (i) Small error: “friend” is false synonym for “acquaintance.” [B:] During [1958-73 in Cuyahoga County], only 23 burglars, robbers or intruders who were not relatives or acquaintances were killed by guns in the hands of persons who were protecting their homes. During this same interval, six times as many fatal firearm accidents occurred in the home. [Article:] a handgun is six times more likely to be used to kill a friend or relative than to repel a burglar [B:] During [1958-73 in Cuyahoga County], only 23 burglars, robbers or intruders who were not relatives or acquaintances were killed by guns in the hands of persons who were protecting their homes. During this same interval, six times as many fatal firearm accidents occurred in the home. (ii) “Handgun” is a false synonym for “gun.” (iii) “Kill a friend or relative” isn’t “fatal firearm accident.” (iv) “Repel” isn’t “kill.” (v) “Burglar” isn’t “burglar, robber or intruder.” (vi) Make clear when you’re inferring from a specific time and place to the whole country at a different time. [Article:] a handgun is six times more likely to be used to kill a friend or relative than to repel a burglar [B:] During [1958-73 in Cuyahoga County], only 23 burglars, robbers or intruders who were not relatives or acquaintances were killed by guns in the hands of persons who were protecting their homes. During this same interval, six times as many fatal firearm accidents occurred in the home. (1) Watch for false synonyms. (2) Watch for inferences from one context to another. (3) Look at the original source (B) and not just the intermediate source (A). (4) Be careful. Be skeptical. [Article:] a person who uses a handgun in selfdefense is eight times more likely to be killed than one who quietly acquiesces [A:] A survey of Chicago robberies in 1975 revealed that, of those victims taking no resistance measures, the probability of death was 7.67 per 1000 robbery incidents, while the death rate among those taking self-protection measures was 64.29 per 1000 robbery incidents. The victim was 8 times more likely to be killed when using a self-protective measure than not! (vi½) Silent generalization from Chicago robberies in 1975 to all crimes at any time anywhere. (vii) Silent inference from “self-protection measures” generally to defensive handgun use. Here’s the actual data on deaths associated with various self-protection measures, from source C: Method of Victim Self-Protection Physical force With Weapon Not a gun Handgun Verbal Denial of goods Verbal Shouting Flight Verbal or Phys. Resis. & Flight Unknown None TOTAL Deaths 7 (6.1%) 0 0 2 (4.5%) 2 (3.7%) 7 (18.9%) 0 23 (79.3%) 7 (0.8%) 48 (3.9%) Total 114 5 6 44 54 37 20 29 913 1222 The “death rate among those taking self-protection measures” (64.29/1000=18/280) says nothing about the death rate among those who use a handgun. [Article:] a person who uses a handgun in selfdefense is eight times more likely to be killed than one who quietly acquiesces [A:] A survey of Chicago robberies in 1975 revealed that, of those victims taking no resistance measures, the probability of death was 7.67 per 1000 robbery incidents, while the death rate among those taking self-protection measures was 64.29 per 1000 robbery incidents. The victim was 8 times more likely to be killed when using a self-protective measure than not! (1) Watch for false synonyms. (2) Check original sources. (3) Avoid confusing language—by surrounding the quoted text with discussion of handguns, source A misled the reader into thinking that the quoted text was talking about handguns.