After reading a passage about Helen Keller, the class breaks into discussion groups. Kylee is a participant in one of the groups. She shares her opinions and uses examples from the text to support them. When she finishes speaking, Kylee begins reading a note from one of her friends. Which participant guideline is Kylee forgetting to follow?

to take turns speaking
to share views and use evidence to support ideas
to act considerately toward others in the group
to stay on topic when speaking

The authors of the paper "fudging the numbers: distributing chocolate influences student evaluations of an undergraduate course"† carried out a study to see if events unrelated to an undergraduate course could affect student evaluations. students enrolled in statistics courses taught by the same instructor participated in the study. all students attended the same lectures and one of six discussion sections that met once a week. at the end of the course, the researchers chose three of the discussion sections to be the "chocolate group." students in these three sections were offered chocolate prior to having them fill out course evaluations. students in the other three sections were not offered chocolate. the researchers concluded that "overall, students offered chocolate gave more positive evaluations than students not offered chocolate." indicate whether the study is an observational study or an experiment. give a brief explanation for your choice.