Question

Researchers at Mississippi State University were studying the impact of different environmental sounds on ecosystems. For their study, they created 333 similar ecosystems in their lab containing a variety of insects and plants. They randomly assigned each ecosystem to be exposed to rock music, country music, or a conventional city soundscape for two consecutive weeks. At the end of the study, they measured how successful the species were in each ecosystem. What type of experiment design is this?

Answer 1

A completely randomized design

Explanation:

The 3 ecosystems were each randomly assigned a treatment. They were not grouped in any way with random assignment happening within each group, so this is a completely randomized design. (From Kahn)