Lets imagine that your vacuum cleaner has stopped working. when it has stopped working in the past, a broken belt was the culprit. since past experience has taught you that the belt is a common issue, you replace the belt again, but this time the vacuum continues to malfunction. you ask a friend to come take a look at the vacuum, and he discovers that one of the hose attachments was not connected, causing the vacuum to lose suction. because of your mental set, you failed to notice a fairly obvious solution to the problem.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

the united states has a federal government. the president is the head of the federal government of the united states. however, each state forms its government for administration purposes. the powers of the state governments are exercised within restricted state boundaries. and citizens participate in this government by voting.

aren't cheetos good enough to be president?

1. senate

2.there is no diagram

3.education