og11-51

ziwingfong

Biometric access-control systems-those using fingerprints, voiceprints, and so forth, to regulate admittance to restricted areas-work by degrees of similarity, not by identity. After all, even the same finger will rarely leave exactly identical prints. Such systems can be adjusted to minimize refusals of access to legitimate access-seekers. Such adjustments, however, increase the likelihood of admitting impostors.

Which of the following conclusions is most strongly supported by the information above?

B.if a Biometric access-control system reliably prevents impostors from being admitted, it will sometimes turn away legitimate access-seekers.

C. Biometric access-control systems are appropriate only in situations in which admittance of impostors is less of a problem than is mistaken refusal of access.

我觉得C更与主题贴近呀，为什么不选？

aegeanyoung

QUOTE:

以下是引用ziwingfong在2007-7-6 14:21:00的发言：

Biometric access-control systems-those using fingerprints, voiceprints, and so forth, to regulate admittance to restricted areas-work by degrees of similarity, not by identity. After all, even the same finger will rarely leave exactly identical prints. Such systems can be adjusted to minimize refusals of access to legitimate access-seekers. Such adjustments, however, increase the likelihood of admitting impostors.

Which of the following conclusions is most strongly supported by the information above?

B.if a Biometric access-control system reliably prevents impostors from being admitted, it will sometimes turn away legitimate access-seekers.

C. Biometric access-control systems are appropriate only in situations in which admittance of impostors is less of a problem than is mistaken refusal of access.

我觉得C更与主题贴近呀，为什么不选？

C说了一个比较.说了impostor被人为是真的,和那些被误诊断的比较.这在文章中没有说.

文章只是说 increase the likelihood of admitting impostors.没有和refusals of access to legitimate access-seekers的比教说明.C是不对的.

flamedream

“by the information above”

并不是只指最后一句话，而是整个题目的信息

ziwingfong

我觉得这个理由牵强，还有更好的解释吗??

windlake

QUOTE:

以下是引用twelvecolors在2007-7-8 6:26:00的发言：

文章说

控制系统是看的相同性不是完全的辨认。这样的好处是：减少了合法的人被拒绝进入的概率。坏处是：增加了冒名顶替者进入的概率。

问conclusion

B：如果冒名顶替人都能被系统挡之门外，那就势必会增加合法的人被拒绝进入的概率--正确

C：冒名顶替人进入的概率小于合法人被拒之门外的概率时，系统才是好的。这点和文章的意思不相符。按C所说，如果合法的人拒之门外的概率如果比冒名者进入的概率大的时候，就是好的。合法的人被拒之门外概率大的话，说明这个系统还是有问题。最理想的情况时两者都很小，但是很显然，由于采取的不是indentify的步骤，所以两者一定时反比关系，一个高另一个一定低。冒名者进入高了，合法人被拒的概率就低。冒名者进入率低了，合法人被拒的概率就高了。因此similarity的access－control的系统是有点问题的。因此C本身不能成立。没人会说，一个合法使用者被拒之门外概率颇高的系统是一个合适的系统。

我觉得楼主对C的解释好像跟原文不太一样吧。原文是说Biometric access-control systems are approporiate only in situations in which admittance of impostors is less of a problem than is mistaken refusal of access. 我想这句话的意思是该系统只有在存伪（允许冒名顶替者）相对于拒真（拒绝合法进入者）是一个更次要的问题时才是合适的。OG说argument并没有谈到approporiate situation，因此尽管从常理上而言，C似乎是对的，但原论述没有提供足够的信息来判断，所以远没有B直接（我是这么理解的）

关于B，我认真想了一下，总结出一条，这其实就是原论述的“逆否命题”，跟原命题就一个意思（OG刚做第一遍，也不知道这么看对不对，请大家指教）

SunnyApples

这题错了几遍，个人觉得，忘了在哪里看到的了，CR的解答不要自己添加自己的想法，不要走的太远,不然“就是哲学，而不是逻辑了”。不知道针对这题，我的看法对不对，NN请来指正。

quejingui77

我也同意说B是原文的逆否命题，而至于C，文中并未说明什么样的系统是approriate所以不对。

我觉得这样考虑能够最快选择出答案。

不知道这样想是不是正确呢？