It is sometimes difficult for the researcher to prove that the specific independent variable caused the dependent variable without any interference from other factors or events. this is one example of problems with:

How did shays' rebellion reveal the need for a revision of the articles of confederation? a) shays' rebellion exposed the weakness of the central government as written in the articles of confederation. b) shays' rebellion strengthened the ideas of the anti-federalists in the need for a strong national government. c) shays' rebellion illustrated the need for organized local government factions to handle situations such as this. d) shays' rebellion encouraged others to rebel and eventually led to the overthrow of the first established government in the united states.