In a study to determine the relationship between self esteem and eating, subjects had been randomly divided into two groups. One group of subjects were individually told something intended to boost their self esteem while in the other group subjects were individually told something intended to lower their self esteem. Each subject was then individually led into a room alone and asked to count the number of chocolate chip cookies in a very large container and told they could eat as many as they liked while conducting their count. Researchers then counted the number of cookies eaten by subjects in each group.

Which of the following statements is true regarding this study? Check all that apply.

This study is an observational study.

This study is blind.

This study is an experimental study.

The treatment was the number of cookies eaten.