Early in the day, you see a fellow student in the cafeteria spill a whole tray of food as she trips over something on the floor. You think to yourself, "Wow, she sure is clumsy!" Later on in the day, you also trip in the cafeteria and spill your tray. You think to yourself, "Wow, this floor is uneven and dangerous, someone should fix it!" This illustrates the psychological concept called:

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.        

an important point to remember about correlation is that while there is a _statistical_ relationship correlation does not equal _causation_

the first answer is: statistical

the second answer is: causation

the awnser is a.

hope this