You Try - Ruins of Tiwanaku (E)

Which one of the following would be most useful to know in order to evaluate the support for the archaeologists’ hypothesis?

The question stem tells us to “evaluate the support” for the argument in the stimulus. In other words, this is an Evaluate question.

The ruins of the prehistoric Bolivian city of Tiwanaku feature green andacite stones weighing up to 40 tons. These stones were quarried at Copacabana, which is across a lake and about 90 kilometers away.

These are the facts. And the facts are in need of an explanation. How did the stones get from the quarry across the lake to Tiwanaku?

Archaeologists hypothesize that the stones were brought to Tiwanaku on reed boats.

Archeologists have a hypothesis. They hypothesize that the stones were transported on reed boats. Okay, I guess that's possible but I don't really see how this is supported. At this point the "reed boat" hypothesis seems to have come out of nowhere.

To show this was possible, experimenters transported a 9-ton stone from Copacabana to Tiwanaku using a reed boat built with locally available materials and techniques traditional to the area.

As we read on, we'll see that there is support. The archeologists ran a demonstration. They transported a 9-ton stone from the quarry to Tiwanaku using a reed boat built with "locally available materials" and "techniques traditional to the area."

Our job is to evaluate the "support" for the hypothesis. In other words, evaluate this argument. In order to do so, we should recognize that this is an argument by analogy. It may not feel as explicit as the previous arguments but nonetheless the reasoning at work is analogical. See, the premise isn't direct archeological evidence of what the builders of Tiwanaku actually did nor documentary evidence. The demonstration that the "experimenters" carried out is relevant only insofar as it closely resembles what the builders of Tiwanaku actually did. That's analogy. The core assumption is that because we were able to do it today, they were able to do it "prehistorically." Is that a good assumption? Well, that all depends on how similar the relevant details are.

There are at least three details that matter.

First is the obvious weight difference. We were explicitly told that the heaviest stones weighed up to 40 tons yet the demonstration only transported a 9-ton stone. That means at best, this reed boat hypothesis is supported as an explanation of how stones up to 9 tons could have been transported. We'd still need to explain stones above that weight.

Second is the fact that these boats were built with "locally available materials." The assumption there is that what's locally available today is the same as or at least similar to what was locally available "prehistorically." Is it? It would be helpful to find out in order to evaluate this argument.

Third is the fact that these boats were built with "techniques traditional to the area." The assumption there is that those techniques were the same as or at least similar to what was used "prehistorically." Again, it's not clear that "traditional" stretches all the way back to "prehistoric." It may, it may not. It would be helpful to find out in order to evaluate this argument.

I'm sure there are other, more subtle details, but having identified these three, we can look at the answers.

Correct Answer Choice (A) whether the traditional techniques for building reed boats were in use at the time Tiwanaku was inhabited.

(A) nails it. It asks about the third detail, whether the traditional techniques were in use at the time of Tiwanaku. If they were, that helps us recognize that the demonstration has at least some similarity to what the builders were doing. If the techniques were not in use at the time, then we can conclude that the demonstration probably isn’t too relevant. Either way, we’re more able to evaluate the strength of the argument.

Answer Choice (B) whether green andacite stones quarried at the time Tiwanaku was inhabited were used at any sites near Copacabana.

Say it with me "Who cares?!" Let's say there was one other site near the quarry called Yunguyo. Let's say that Yunguyo also used those stones. That doesn't help us evaluate the argument for the reed boat hypothesis. Let's now say that Yunguyo did not use those stones. That also doesn't help us evaluate the argument for the reed boat hypothesis. All of that is what we mean when we declare, with exasperation, "Who cares?!"

Answer Choice (C) whether reed boats are commonly used today on the lake.

Okay, you got it. Say it loud and clear. Make me proud. “Who cares?!” We’re trying to figure out if the reed boat demonstration is analogous to prehistoric techniques, so what people are doing today really has no bearing either way.

Answer Choice (D) whether the green andacite stones at Tiwanaku are the largest stones at the site.

It doesn't matter. Let's say that they were. Okay, we haven't moved an inch on evaluating the original argument. Let's say that they were not. Let's say that red sandstone at Tiwanaku were way larger, like 100 tons. Again, we haven't moved an inch on evaluating the original argument. The original argument is all about and only about the green andacite stones. I'm sorry to say this (D), but nobody cares about you.

Answer Choice (E) whether the reed boat built for the experimenters is durable enough to remain usable for several years.

Yeah, okay we also don't care about this. Had it been a stipulation that the original boats must have been in use for several years, then this would have been a relevant point of similarity. But there was no such stipulation and we have no reason to assume it.