An effective theory must be:

a) able to explain cause and effect
b) based on associations
c) based on quantitative data
d) inclusive and testable

1 answer

d) inclusive and testable

An effective theory should be able to provide a comprehensive explanation for a particular phenomenon, be testable through empirical evidence, and be able to predict future observations. Quantitative data and cause-and-effect relationships may be important components of a theory, but ultimately it must be inclusive and able to be tested in order to be considered effective.