The effect of adding fluoride to a community's water supply was tested by comparing annual records of cavities per patient in local dentists’ offices for six years before and four years after the fluoride was added. This is an example of which type of research?

a. Interrupted time series
b. Regression discontinuity
c. Propensity score matching
d. Cross-sectional comparison

a. Interrupted time series

Political Science

You might also like to view...

Ethnic Koreans are considered Japanese citizens if they or their parents were born in Japan

Indicate whether this statement is true or false.

Political Science

All states in the United States offer some form of the initiative process.

Answer the following statement true (T) or false (F)

Political Science