Question

The article "Thirsty World" from Science News 08/18/2018 Vol. 194 issue 4, p14-17 talks about the worlds safe water and sanitation. Is this an observation study or experimental study?

Answer 1

Observational study:

Like experiments, observational studies attempt to understand cause-and-effect relationships. However, unlike experiments, the researcher is not able to control (1) how subjects are assigned to groups and/or (2) which treatments each group receives.

Experimental study:

An experiment is a controlled study in which the researcher attempts to understand cause-and-effect relationships. The study is "controlled" in the sense that the researcher controls (1) how subjects are assigned to groups and (2) which treatments each group receives.

In the given article researcher can not control the situation, they just study its causes and effects.

Hence it is an observational study.