RBBmba@2014 wrote:In GMAT CR the BOTTOM-LINE is:
1. For ASSUMPTION CR - the OA is a MUST BE TRUE STATEMENT, which has to be also a NEW INFORMATION at the same time.
I think that you have a good general understanding of the idea, but just to be semantically precise...
An ASSUMPTION does
not have to be NEW information. The right answer
can contain new information, but usually only if it's RULING OUT alternative possibilities. Consider:
OG 2016 #40:
Argument: If the county continues to collect residential trash at current levels, landfills will soon be overflowing and parkland will need to be used in order to create more space. Charging each household a fee for each pound of trash it puts out for collection will induce residents to reduce the amount of trash they create; this charge will therefore protect the remaining county parkland.
Assumption: The collection fee will not induce residents to dump their trash in the parklands illegally.
Dumping trash in the park is new info, and the right answer specifies that it will NOT happen.
In this next example, I would argue that the right answer isn't really "new" information, it's a reinterpretation / clarification of the information given:
OG 13/2015 #77:
Argument: A recent report determined that although only 3 percent of drivers on Maryland highways equipped their vehicles with radar detectors, 33 percent of all vehicles ticketed for exceeding the speed limit were equipped with them. Clearly, drivers who equip their vehicles with radar detectors are more likely to exceed the speed limit regularly than are drivers who do not.
Assumption: Drivers who are ticketed for exceeding the speed limit are more likely to exceed the speed limit regularly than are drivers who are not ticketed.
Here, the argument hinges on the specification of the word "regularly."
For your second point,
2. For STRENGTHEN/WEAKEN CR - the OA is just a NEW INFORMATION only. But NOT necessarily, a FACT or PREMISE.
I would reword this to say:
2. For STRENGTHEN CR - the OA is just NEW INFORMATION that makes the link between premise and conclusion (and the the argument as a whole) MORE LIKELY to be true... but it is NOT something that MUST be true for the argument to be valid.
For WEAKEN CR - the OA is NEW INFORMATION that makes the link between premise and conclusion (and the the argument as a whole) LESS LIKELY to be true.... but it is NOT something that DISPROVES the argument.