In an experiment, one thousand nine-year-old children were allowed to

Question

In an experiment, one thousand nine-year-old children were allowed to choose whether to participate in a program in which the researchers taught them dance during the daily break from their lessons. Four hundred of the children chose to participate for at least one year. At the end of the year, researchers found that the children who had participated had significantly better balance, on average, than those who had not. The researchers hypothesized that dancing resulted in a sustained improvement in the children's sense of balance.

It would be most helpful in evaluating the researcher's hypothesis to know whether the researchers ___1___ prior to having __2__.

Select Researchers for the phrase that fills the blank labeled 1 in the given statement, and select Prior to for the phrase that fills the blank labeled 2 in the given statement to create the most accurate statement on the basis of the information provided. Make only two selections, one in each column.

1:Researchers | 2: Prior to
0 0 tested the children's ability to dance
0 0 designed a second experiment
0 0 divided the children into the two experimental groups
0 0 tested the children's sense of balance
0 0 taught dance to the children through the dance program

Hi, I found this question hard. In fact, not sure where to start with.
Can anyone explain this for me, please.

OA

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1: tested the children's sense of balance
2: taught dance to the children through the dance program

eshan429 · Accepted Answer

According to the passage, the researchers compared the ability to dance of children who took dance classes to those who did not and concluded that dance improved their balance. It might also be the case that the children who took up dance had better balance even before starting the classes. It would be helpful to know how the two groups performed in terms of balance before the classes started to better evaluate the conclusion.

So, the correct answer should be It would be most helpful in evaluating the researcher's hypothesis to know whether the researchers tested the children's sense of balance prior to having taught dance to the children through the dance program.

So, the correct answer should be It would be most helpful in evaluating the researcher's hypothesis to know whether the researchers  tested the children's sense of balance  prior to having  taught dance to the children through the dance program .

ChiranjeevSingh · Answer

Understanding the Argument   
 In an experiment, one thousand nine-year-old children were allowed to choose whether to participate in a program in which the researchers taught them dance during the daily break from their lessons. 
 
 Experiment: children given the choice to participate in dance tutoring

Four hundred of the children chose to participate for at least one year. 
 
 400 (out of 1000) chose to participate for at least 1 year. 
 The remaining 600 did not.

At the end of the year, researchers found that the children who had participated had significantly better balance, on average, than those who had not. 
 
 This option compares the children who had participated in the program (those 400 children) and the children who hadn’t participated in the program (those 600 children) 
 Interestingly, the basis of comparison is not the ability to dance, which they were taught. The basis of comparison is how much balance children had. (If you are not reading the passage carefully, you may end up assuming that the comparison is about the ability to dance.) 
 Those 400 children had much better balance, on average, than those 600 children.

The researchers hypothesized that dancing resulted in a sustained improvement in the children's sense of balance. 
 
 The hypothesis is that dancing caused improvement in children’s sense of balance. 
 The hypothesis is supported by the previous observation that the children who had participated in dance tutoring (and thus danced) had better balance than the children who had not participated in dance tutoring (and thus perhaps did not dance).  
     Gaps in the Argument   
I can see that this argument is a typical correlation-to-causation argument in which the premise is a correlation between dancing and balance, and the conclusion is a causation statement that dancing caused better balance.

Besides, we don’t even know whether the 600 children (who didn’t participate in the program) danced less during the year than the 400 children who participated. It is possible that those 600 children danced more through other programs or on their own.
   Understanding the Question Stem   
It would be most helpful in evaluating the researcher's hypothesis to know whether the researchers   1   prior to having   2  .

We’re trying to evaluate the researcher’s hypothesis and looking for options that will fit into the blanks to help us evaluate the hypothesis.

The first blank will be something like WHAT RESEARCHERS DID prior to having DONE SOMETHING ELSE

Together, the statement created with the filled blanks will help us evaluate the researchers’ hypothesis.

Select  Researchers  for the phrase that fills the blank  labeled 1  in the given statement, and select  Prior to  for the phrase that fills the blank  labeled 2  in the given statement to create the most accurate statement on the basis of the information provided. Make only two selections, one in each column.   Evaluating the Options

A. tested the children's ability to dance 
 
 It’s a very tempting choice for people who didn’t read the passage carefully. 
 Even though the argument talks about teaching dance, it is NOT CONCERNED about the children’s ability to dance. 
 The argument talks ONLY about the sense of balance caused by dancing. 
 Researchers’ testing the children’s ability to dance WILL NOT help us evaluate the argument about whether dancing helps children become balanced.

B. designed a second experiment 
 
 How will we evaluate the argument by knowing that the researchers designed a second experiment WITHOUT KNOWING how the experiment will help us evaluate the argument. 
 Of course, a helpful experiment can be created to evaluate the argument. 
 However, the option doesn’t say that experiment will help us evaluate the argument in any way. 
 The option talks only about designing a second experiment. 
 Designing a second experiment in itself will not help.

C. tested the children's sense of balance 
 
 Testing the balance makes sense since this argument is about whether dancing builds children’s sense of balance. 
 However, to select this option for the first part, I need to find the appropriate second part. 
 So, I’ll keep this on hold while I look at the other options.

D. taught dance to the children through the dance program 
 
 We know that the researchers taught dance to children through the dance program 
 So, this part may fit in the second label. 
 Let’s read C and D together → Researchers tested the children's sense of balance prior to having taught dance to the children through the dance program. 
 In this case, researchers will have data about the balance of childrens in two groups. 
 If the group that did not participate had better or the same balance before the dance program, then the argument would be strengthened. (After the program, we’re given that the children who participated in the program had better balance. Thus, in this case, we’ll believe more in the idea that the program (or dancing) bettered the children’s sense of balance.) 
 If the group that did not participate had a worse balance before the dance program, then the argument would be weakened. In this case, the group that participated in the dance program had better balance to begin with. So, we cannot say that dancing bettered their balance.

GuptaDarsh · Answer

Hi, I found this question hard. In fact, not sure where to start with.
Can anyone explain this for me, please.

Hi  goodyear2013 
The passage says that, researchers "taught dance to childerne" and after one year they concluded that the children who had participated had significantly better balance, on average, than those who had not. And thus Dancing helped
Now as the result is based on the "average", if some of the children who took the program already knew dancing then the resulted average would stand incorrect.
Therefore Ans :
the researchers ___1.tested the children's ability to dance___ prior to having __2.taught dance to the children through the dance program__.

Hope it helps.

Shrivathsan · Answer

For the first one i got it correct
 but second i got stuck between c and e.

Even C fits perfectly.
Prior to divide into 2 experimental groups will tell me how   children who had participated had significantly better balance, on average, than those who had not  .

Since we are talking about sustained improvement are we going with E ?

ZenYogi · Answer

IMO, C is incorrect because, it implies that comparing the two groups is still the best way to conclude whether the dance lessons led to an improvement. However, this is not the best method, as it may be the case that students who took lessons (group A) did not improve, but those in the other group (group B) declined in their ability. Or, it may be that group A declined in their ability, but it was still far better to begin with. E is a good choice, because it directly determines whether dance lessons led to an improvement by only focusing on group A.

PReciSioN · Answer

Sajjad1994 , the official question (OG23-24) does infact contain option-C. Could you make the changes please in the question here? Thanks!

GMATNinja wanted to confirm that option-C does infact exist. Also, do you reckon that E is better than C, since we want to know strictly the effect of only the dance training period on their balance (since that is what the hypothesis entails), and that C includes an additional time-period (although possibly small), that might involve factors outside dancing affecting their balance. (example - after choosing to go in the dancing group, some students practice their balance skills which improves their skills, but it isn't strictly due to dancing.)

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Attachment:

GMAT-Club-Forum-k8587m1c.png [ 77.74 KiB | Viewed 4309 times ]

Bunuel · Answer

Added the option. FYI, the two part analysis questions can have 5 or 6 options only. GMAT-Club-Forum-ausrgro8.png

GMATNinja · Answer

Thanks for the confirmation!

You make a good point -- maybe the students who signed up for the dance class decided to do some balance training in preparation for the course.

Another issue with (C) is that it implies that the scientists DIVIDED the students into two experimental groups: that's not quite accurate, since the students were allowed to choose.

Even if you think (C) is fair game, (E) is a better answer, since, as we stated earlier in the thread, it speaks more directly to what's important: the balance testing happened before the dance instruction.

In short, there are a couple not-so-great reasons to pick (E) over (C), but there are NO good reasons to pick (C) over (E). So (E) is our winner.

I hope that helps!

KarishmaB · Answer

It is simply a CR question based on "studies conducted" testing a concept we have seen tested often in CR. In an experiment, 1000 children were allowed to choose whether to participate in a program in which the researchers taught them dance. 400 chose to participate. At the end of the year, researchers found that the children who had participated had significantly better balance, on average, than those who had not. Conclusion: Dancing resulted in a sustained improvement in the children's sense of balance. What is our problem here? That the children were given the choice. What if children who choose to dance are the ones who naturally have better balance? Because of their better balance, they enjoy dancing more and do a better job at it and hence they feel like dancing. Basically, when we are comparing two groups, the groups must be unbiased samples, they must be equivalent. Here they are not. Had the researchers instead taken two unbiased groups of children which were fair representaion of the population and then made one group dance, there was a better chance of proving the point. Hence testing the groups for their balance before the dance sessions was important - to know whether both groups represent the population fairly or whether one group has naturally better balance than the other. Also, there is a natural, automatic division of the groups here - those who wanted to dance and those who did not. There is no question of researchers dividing into two groups. GMAT-Club-Forum-1ebcv6pn.png

egmat · Answer

This is a tricky question that tests whether you can identify what information would actually help evaluate a causal claim. Let's work through this together.

Understanding What They're Really Asking

The researchers are making a bold claim: that  dancing caused  sustained improvement in balance. But notice what actually happened - they let kids choose whether to participate, then measured balance at the  end  and found dancers had better balance.

Here's the million-dollar question: Did dancing improve their balance, or did kids with naturally better balance choose to dance?

Step 1: Identify the Core Problem

The major flaw here is  self-selection bias . The passage says children were "allowed to choose" - they weren't randomly assigned. This means:
 
 Maybe kids who already had good balance felt more confident and chose to dance 
 Maybe kids with poor balance avoided the program 
 The difference we see at the end might have existed from the start

Step 2: What Would Actually Help Evaluate This?

To know if dancing  caused  the improvement, you'd need to know whether the groups were comparable at the beginning. Think about it - if the dancers already had better balance before the program started, then the hypothesis falls apart.

So you'd want to know: Did researchers measure baseline balance before the intervention?

Step 3: Build the Right Temporal Sequence

The sentence structure asks for: "researchers _____ prior to having _____"

The most useful information would be:
 
  Part 1:  "tested the children's sense of balance" 
  Part 2:  "taught dance to the children through the dance program"

This creates the logical sequence:  Test baseline → Implement program → Compare results

If both groups had similar balance scores before the dance program, and only the dancers improved during the year, that would  support  the causal hypothesis. But if the dancers already had superior balance at baseline, that would  seriously weaken  the claim that dancing caused the improvement.

Watch Out for This Trap!

"Divided the children into the two experimental groups" sounds tempting because it relates to experimental design. But notice two problems:
 
 The children divided  themselves  through self-selection - researchers didn't divide them 
 More importantly, just knowing about how groups formed doesn't tell you if they were initially comparable

The answer you need directly addresses whether pre-existing differences could explain the results.

The Complete Answer: 
"It would be most helpful to know whether the researchers  tested the children's sense of balance  prior to having  taught dance to the children through the dance program ."

This gives exactly what's needed to evaluate the causal claim - baseline measurements before the intervention.

Want to Master This Question Type?

I've walked you through the core logic here, but there's a broader systematic framework for tackling all "evaluate the argument" questions that you'll find invaluable. The  complete solution on Neuron by e-GMAT  breaks down the pattern-recognition approach that works across similar CR questions, plus shows you how to systematically identify experimental design flaws. You can also practice with detailed solutions for  many other official questions on Neuron  with comprehensive analytics to track your progress.

Hope this helps! Let me know if you have questions about the approach.

manish8242 · Answer

Why the answer can't be C for the second part? Before dividing the group? It must be that The researcher need to check the balance skill prior to dividing the group.

Bunuel · Answer

C cannot be right because the study did not involve the researchers dividing anyone. The children self-selected. There is no “division” event to place the baseline test before.

What matters for evaluating the hypothesis is whether balance was tested  before  the dance lessons began. That’s the only meaningful starting point. Therefore, D with E works best: test the children’s balance first, then begin teaching dance. This shows whether any difference existed initially or developed after the program.

This is also addressed in several posts above.

egmat · Answer

manish8242  I can see why "before dividing the group" seems logical, but let me explain why  "prior to teaching dance"  is actually the better answer.

Understanding the Timeline:

Here's what happened in the experiment:

Children self-selected into groups  (400 chose dance, 600 didn't) 
  Dance program was taught  to those who chose to participate 
  Balance was measured  at the end of the year

The Core Problem: Self-Selection Bias

The researchers claim dancing  caused  improvement in balance. But there's an alternative explanation:

What if children who already had better balance were more likely to choose dancing?

Maybe kids with good balance feel more confident about dance and select the program, while kids with poorer balance avoid it.

What Information Would Help Evaluate This?

We need to know:  Did the two groups have similar balance BEFORE the dance teaching began?

Here's the key: By the time the dance program starts, the groups have  already formed  through self-selection. So we need to test balance at this point – after self-selection but before teaching.

Why "Prior to Teaching Dance" is Correct:

If researchers tested balance  after groups formed but before teaching dance :

Scenario 1:  Both groups had similar balance at baseline
→ The better balance in the dance group afterward  supports  the hypothesis that dancing caused improvement

Scenario 2:  The dance group already had better balance at baseline
→ This suggests self-selection bias,  not supporting  the hypothesis that dancing caused the difference

Either way, this information  directly evaluates  whether dancing caused the improvement.

Why "Prior to Dividing Groups" is Less Useful:

Testing balance  before  children chose (when all 1,000 were still together) would show us the overall baseline, but it doesn't tell us about the  comparison between the two groups that eventually formed .

Think about it:
 
 If we test all 1,000 kids before they choose, we get individual balance scores 
 But we don't yet know which 400 will choose dance and which 600 won't 
 We can't compare the groups because the groups don't exist yet

What we really need is:  "Did the dance group and non-dance group have similar balance right before the intervention started?"

This is measured  after  self-selection (so groups exist) but  before  teaching (so the intervention hasn't occurred yet).

Hope this addresses your doubt clearly!

In an experiment, one thousand nine-year-old children were allowed to

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1: Researchers	2: Prior to
		tested the children's ability to dance
		designed a second experiment
		divided the children into the two experimental groups
		tested the children's sense of balance
		taught dance to the children through the dance program

GMAT Two-part Analysis (TPA) Questions

In an experiment, one thousand nine-year-old children were allowed to

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615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

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