What is Imperial Presidency?

Factorial designs are used when

A) only one independent variable is included in the study. B) more than one independent variable is included, and interactions as well as main effects are expected. C) only main effects are expected. D) there is no possibility of extraneous variables.

The Clean Water Act of 1972 was put into place to protect fish and wildlife, to eliminate the discharge of pollutants into the water and to

A) allow chemical filtration of lakes. B) eliminate the use of navigable waters by migratory birds. C) eradicate the use of well water. D) reduce lead levels in drinking water. E) make waters safe for swimming.