1) Near-sightedness typically develops during the childhood years. Recent studies have investigated a possible association between near-sightedness and
the use of night- lights with infants. In a study by Quinn, Shin, Maguire, and Stone
(1999), researchers surveyed parents of 479 children visiting a pediatric
ophthalmology clinic. One of the questions was "Under which lighting condition
did/does your child sleep at night?" before the age of 2 years. The parents chose
between "room lighting," "a night light," and "darkness." Based on the child's
most recent eye examination, researchers separated the children into three
groups: near-sighted, normal refraction, or far-sighted.
a) Who are the individuals of interest in thisstudy?
b) What is the explanatory variable in this study? Is it quantitative or
categorical?
c) What is the response variable in this study? Is it quantitative or categorical?
d) Is this an observational study or an experiment? How can you tell?
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