What technique is the key to the accuracy of public opinion polls?

A probability sampling technique in which a researcher begins by identifying subgroups and then randomly samples from each groups is called probability sampling

a. stratified b. cluster c. simple d. systematic

A key problem in the relationship between Congress and the president concerning war powers stems from the fact that ______.

a. they each have the power to declare war b. only the president can order troops overseas c. the president has preempted congressional control over the military d. the president is commander-in-chief, but Congress has the power to declare war e. the courts refuse to rule on the issue