No evidence for a claim does not mean the claim is false.
No evidence against a claim does not mean the claim is true.
Some evidence for a claim does not mean it is true.
Some evidence against a claim does not mean it is false.
10. Survey errors
A) Biased or unrepresentative samples
When studying a certain groups, researchers must survey a random sample of that group or the survey results will be flawed.
Researchers can err by choosing people who are likely to represent only a subset of the entire group or by letting people voluntarily respond. Either way, the sample is not random and thus unrepresentative.
Example: Randomly polling subway riders all across the country to determine whom Americans will likely elect as President will probably not account for rural voters, who tend to vote differently than urban voters.
B) Biased questions
Tempting: “Do you support reasonable reform?” encourages respondents to say they do because to say otherwise would be “unreasonable.”
Misleading: “Do you think we should kill Osama bin Laden or stop searching for him?” suggests we have only two choices. (Well, now we do not need to worry about this question any more!)
Confusing: “Do you have a higher elasticity for bread or cheese?” is really asking, “Are you more sensitive to a change in price for bread or cheese?” or, better yet, “Which food prices do you monitor more closely?”
C) Biased answers
Example: In the 2008 Presidential primaries, polling critics questioned polls that showed Barack Obama leading Hillary Clinton. They argued that the respondents were likely overstating their support for Obama because they did not want to appear racist.
11. Generalizations
The passage makes an unwarranted generalization based on only one or two examples.
Flawed example: “Poor people will go from rags to riches. Felix Dennis did.”
Sound example: “Poor people can go from rags to riches. Felix Dennis did.”
12. Quantity vs. percentage
When both number and percentage are stated and compared in the same passage, pay extra attention to what can be said in the comparison. Simple math would solve some seemingly complex CR problems.
Example: “Tom was paid twenty percent more this year than last year, while his administrative assistant, Sally, was paid only ten percent more. Therefore, Tom was paid more this year than Sally was.” What if Tom’s initial salary was less than half of that of Sally?
13. Parts vs. whole
What is true for the parts might not be true for the whole: “Every part of this car is well built, so this car is well built.”
What is true for the whole might not be true for the parts: “Apple sells only computers. So every Apple sales representative sells only computers.”
What is true for some parts might not be true for the other parts: “May cat cleans herself daily. So all cats clean themselves daily.”
14. Past vs. future: “The bus has never been late. It will be on time today.”
15. Using the same word twice in the argument but with different meanings.
16. False choice
When a passage argues A is the right choice because A and B are the only options and B won’t work, make sure A and B are the only options. If not, the argument relies on a false choice.
17. False analogy
Analogies are always different than the claim they support. But false analogies are different in some important respect.
C) Biased answers ? Example: In the 2008 Presidential primaries, polling critics questioned polls that showed Barack Obama leading Hillary Clinton. They argued that the respondents were likely overstating their support for Obama because they did not want to appear racist.
I did not find some thing like biased answers in the example. Can someone help me?
? Analogies are always different than the claim they support. But false analogies are different in some important respect.
I did not make sense this sentence. What dose sd want to say ?作者: 橘子树的冬天 时间: 2011-7-5 22:57
赞！！作者: x110hp 时间: 2011-7-6 11:08
终于更新了，谢谢LZ，等很久了！作者: jianaozhonghua 时间: 2011-7-7 06:10
NN，什么时候出evaluate？作者: jameshzd 时间: 2011-7-8 10:50
i come too late ! what a pity !作者: MarsTOF 时间: 2011-7-15 16:34
连AWA一起练习了！！哈哈作者: bonfin 时间: 2011-10-31 10:45
up作者: 月照琳琅 时间: 2011-11-3 21:03 作者: 泾渭不凡 时间: 2012-2-3 04:34
flaw部分要一气呵成看完啊~~
C) Biased answers ? Example: In the 2008 Presidential primaries, polling critics questioned polls that showed Barack Obama leading Hillary Clinton. They argued that the respondents were likely overstating their support for Obama because they did not want to appear racist.
I did not find some thing like biased answers in the example. Can someone help me?
I think that means the poll result from the respondents is not credible, because the respondents might support Obama for some special considerations(they didn't want to appear racist).作者: smilerongrong 时间: 2012-3-18 19:58
其实看的有点儿吃力……作者: 女王的肥皂 时间: 2012-6-14 12:17
9. Overstating the evidence ? No evidence for a claim does not mean the claim is false. ? No evidence against a claim does not mean the claim is true. ? Some evidence for a claim does not mean it is true. ? Some evidence against a claim does not mean it is false.
I have one question about the last judgement.
I think if one evidence is existed agaisnt a claim, then I can say the claim is false.
thx sdcar!