Can moving their hands help children learn math? This is the question
investigated by the authors of the paper "Gesturing Gives Children New Ideas
about Math" (Psychological Science [2009]: \(267-272\) ). An experiment was
conducted to compare two different methods for teaching children how to solve
math problems of the form \(3+2+8=\ldots+8\). One method involved having
students point to the \(3+2\) on the left side of the equal sign with one hand
and then point to the blank on the right side of the equal sign before filling
in the blank to complete the equation. The other method did not involve using
these hand gestures. The paper states that the study used children ages 9 and
10 who were given a pretest containing six problems of the type described.
Only children who answered all six questions incorrectly became subjects in
the experiment. There were a total of 128 subjects. To compare the two
methods, the 128 children were assigned at random to the two experimental
conditions. Children in one group were taught a method that used hand
gestures, and children in the other group were taught a similar strategy that
did not involve hand gestures. Each child then took a test with six problems
and received a score based on the number correct. From the resulting data, the
researchers concluded that the average score for children who used hand
gestures was significantly higher than the average score for children who did
not use hand gestures.
a. Answer the following seven questions for the experiment described above.
(Hint: Reviewing Examples 1.5 and 1.6 might be helpful.)
1\. What question is the experiment trying to answer?
2\. What are the experimental conditions (treatments) for this experiment?
3\. What is the response variable?
4\. What are the experimental units and how were they selected?
5\. Does the design incorporate random assignment of experimental units to the
different experimental conditions? If not, are there potentially confounding
variables that would make it difficult to draw conclusions based on data from
the experiment?
6\. Does the experiment incorporate a control group and/or a placebo group? If
not, would the experiment be improved by including them?
7\. Does the experiment involve blinding? If not, would the experiment be
improved by making it single- or double-blind?
b. Based on the study design, do you think that the conclusions are
reasonable?
