在GRE写作中，最经常出现的错误就是逻辑错误，那么下面小编就来和介绍一下吧!

　　1、结论无据(gratuitous assumption)

　　The author falsely depends on gratuitousassumption that.... However, no evidence is stated in the argument to supportthis assumption. In fact, this is not necessarily the case. For example, it ismore likely that.... Therefore, this argument is unwarranted without ruling outsuch possibility.

　　2、无因果联系

　　The author commits a fallacy of causaloversimplification. The line of the reasoning is that because A occurred beforeB, the former event is responsible for the latter. (The author uses thepositive correlation between A and B to establish causality. However, the factthat A coincides with B does not necessarily prove that A caused B.) But thisis fallacious reasoning unless other possible causal explanations have beenconsidered and ruled out. For example, perhaps C is the cause of these eventsor perhaps B is caused by D.

　　3、样本不足(Insufficient-sample)

　　The evidence the author provides isinsufficient to support the conclusion drawn from it. One example is logicallyunsounded to establish a general conclusion (The statistics from only a fewrecent years are not necessarily a good indicator of future trends), unless itcan be shown that A1 is representative of all A.

　　4、二者择一(Either-Orchoice)

　　The author assumes that AA and BB aremutually exclusive alternatives and there is no room for a middle ground.However, the author provides no reason for imposing an either-or choice. Commonsense tells us that adjusting both AA and BB might produce better results.

　　5、错误类比 (based on a false analogy ) <横向>

　　The argument rests on the assumptionthat A is analogous to B in all respects. This assumption is weak, sincealthough there are points of comparison between A and B, there is muchdissimilarity as well. For example, A..., however, B.... Thus, it is likelymuch more difficult for B to do....

　　6、时地全等 all thingsare equal <纵向>

　　The author commits the fallacy of “all things are equal”. The fact thathappened two years ago is not a sound evidence to draw a conclusion that....The author assumes without justification that the background conditions haveremained the same at different times or at different locations. However, it isnot clear in this argument whether the current conditions at AA are the same asthey used to be two years ago. Thus it is impossible to conclude that....

　　7、可疑调查(survey isdoubtful)

　　The poll cited by the author is toovague to be informative. The claim does not indicate who conducted the poll,who responded, or when, where and how the poll was conducted. (Lacking informationabout the number of people surveyed and the number of respondents, it isimpossible to access the validity of the results. For example, if 200 personswere surveyed but only 2 responded, the conclusion that...would be highlysuspect. Because the argument offers no evidence that would rule out this kindof interpretations,) Until these questions are answered, the results of thesurvey are worthless as evidence for the conclusion.