Question

**Question 1\.\** The data were gathered by the following procedure, reported in the study. "Between January and June 1998, parents of children aged 2-16 years [...] that were seen as outpatients in a university pediatric ophthalmology clinic completed a questionnaire on the child’s light exposure both at present and before the age of 2 years." Was this study observational, or was it a controlled experiment? Explain.

Answer 1

OBSERVATIONAL

Explanation:

Let`s see the two kind of experiments mentioned:

• Observational experiments: are those where individuals are observed or certain outcomes are measured. There is no intervention by the scientist, for example: no treatment at all is given

• Controlled experiments: Are those experiments that are directly manipulaed by the sciencist in order to study the controlled variable's reaction or change.

In this case, the patient's parent only answer a questionnairewith no intervention from the doctors into the pacients at all, so it's an observational experiment