yoni45 wrote:The example was in reference to something else, so it definitely wouldn't apply. A quick search brings up this one that seems like it should work though... PT32, S4, Q14.
The stimulus provides a specific case in which something that, for at least one purpose, is theoretically superior is also practically inferior. In other words, we know that at least in some cases, ideas that work well in theory don't work that well in practice.
Answer choice (A) states that "many" ideas that work well in theory don't work well in practice. But, we only know that this is true in some cases, not necessarily in many. (A) is incorrect.
Actually I don't buy that. According to that question what you know is two things:
(1) a analog systems are theoretically better than digital
(2) that (1) entails "a
practical disadvantage" (this last bit is verbatim)
there is a difference between something 'having a practical disadvantage' and 'not working well in practice'. Specifically, that difference is that having a practical disadvantage only entails one aspect of practicality that is lacking, while 'not working well in practice' is a blanket statement. We cannot even say that SOME things that work theoretically do not work well in practice because the stimulus does not give us enough information to deduce that. What we can deduce is that there is a SINGLE scenario where digital recordings have an advantage OVER analog, but not that analog recordings do not work well in practice.
This point hits up the difference between relative statements and absolute statements. If I say that mondays are hotter than tuesdays, I can't say that mondays are hot or that tuesdays are cold because we lack an absolute statement about what constitutes hot or cold.
In our case here we only have a relative 'practical disadvantage' since this disadvantage is based on the relative claim that 'analog systems are more precise than digital systems'. This 'disadvantage' is nowhere stated to be enough to say that 'analog systems do not work well in practice'. In fact, this disadvantage is further qualified later to be confined to the making of duplicate recordings. In order to conclude A, therefore, we would need an additional statement such as 'practicality of making a large number of duplicate recordings is indicative of whether a system works well in practice' or something to that effect.
edit: i guess my main point (if you don't want to read all of the above) is that if something 'has a practical disadvantage'
that does not suggest that that something does 'not work well in practice'