The correct answer: B
Argument Analysis:New handheld device -
a) the claim is that it will be able to determine the severity of a concussion
b) it will be able to do this by reading the electrical signals from a brain of a person who has suffered a blow to the head and comparing them to a database of 15000 scans from a brain research lab
c) the device is intended to help doctors on the field decide whether an athlete who has been hit on the head should be sent back to the game, or not
Question: What will help us evaluate the usefulness of the device for its intended purpose?
Prethinking:Conclusion to evaluate - the device will help doctors decide whether an athlete who has been hit on the head should be sent back to the game, or not
In what scenario would the device not really serve the intended purpose?
What if 1500 scans is not sufficient for a proper and accurate reading from the device? Then this device cannot be trusted. It reduces the belief that this device will be able to help doctors make an effective decision.
Statement: Whether 15000 scans is a sufficient number of scans for the device to give accurate results?If YES - increases our belief
if NO - reduces our belief
Option Choice Analysis:A. Whether the database of brain scans will regularly be updated with new scans
It does not help validate the argument. For all we know, 15000 scans which are already in the database are more than sufficient. Whether the database gets regularly updated is not relevant to the argument about whether the device, as it stands, will achieve its purpose
B. Whether by use of this device doctors will be able to make a sound decision about whether to allow an athlete back into the competition before it ends
Correct. Not exactly what we pre-thought (different point), but still the correct answer here. Let us apply the variance test.If YES - Doctors will be able to make a proper decision based on this device i.e. the device is effective for its intended purpose.
If NO - Doctors will not be able to make a proper decision based on this device. It reduces our belief in the notion that the device will be able to achieve its intended purpose.
This option seems correct.
C. Whether the device will be endorsed by a large number of medical professionals
Irrelevant. Endorsement of the device may help get more sales, but it tells us nothing about whether the device is effective for its intended purpose.
D. Whether the database includes scans of non-injured athletes in the same game as the injured athlete
This can be a tricky option. A database for comparing level/severity of concussion in all probability should include scans of non injured (0 concussion) cases all the way to highest extremes of concussion. So, a database of this type is a necessity. But just because a necessary condition is met, do we have any idea if the device is effective? There could be other important necessary conditions to make the device effective. There is a difference between the device being operational/usable to the device being effective. So, we are not sure. It may still weakly increase our belief in the conclusion, though. So let us hold on to this for a while
Now - "in the same game". Is this required? We have no idea if scans of non injured athletes has to be from the same game (say rugby). Why not from another sport like Ice Hockey? If scans are from different games, will it impact the quality of the scans? the impact is unclear. This is a red flag as far as option D is concerned.
Let us apply the variance test
If YES - the database includes scans of non-injured athletes from the same game, and injured athletes.
- Non injured scans are definitely important for the device to work, but we are not sure how much it will help with regard to effectiveness. At best, this mildly increases our belief. At worst, it has no real impact on effectiveness. Lets hold on to this for now.
If NO - the database does not include scans of non-injured athletes from the same game, and injured athletes.
- Even in such a case, maybe the database has scans of "non-injured" athletes from other games (say, ice hockey instead of rugby). And for 0 concussion/non injury cases, for all we know, this is more than enough to make the device effective.
In other words, this option fails the variance test. Even if the YES side increases our belief (albeit weakly), it is very possible that the NO side does not decrease belief.
Hence option D is not correct.
E. Whether team doctors have until now been mistaken in their assessments of whether an athlete can safely continue to play
Previous mistakes are not relevant to evaluating whether now, with the help of this device, the doctors will be able to make a sound decision. Irrelevant.
Hope this helps.
Regards