Patronage has been restricted over the years by the ________

Suppose two groups really differed from one another with respect to a dependent variable but did not act differently in an experiment because an unknown variable affected one of the groups. This problem could result from

a. the presence of a confound. b. causal ambiguity. c. experimenter bias caused by double blind. d. lack of divergent validity.

The recorded votes on major amendments and final passage of bills are called _____ votes

a. cloture b. committee c. concurrent d. roll call e. trustee