24 0.33 points
Suppose a researcher believes that the presence of a floral scent can improve a person's learning ability in certain situations. He randomly samples 30 people and has them work
through a pencil and paper maze two times, first wearing an unscented mask and then wearing a scented mask. Tests measured length of time it took subjects to complete each
of the two trials. They reported that, on average, subjects wearing the floral-scented mask completed the maze more quickly than those wearing the unscented mask. Which of
the following statements is true?
The results of this study cannot be trusted, because the participants always wear the scented mask the second time they complete the maze, making practice (knowledge
of the maze) a confounding variable.
The results of this study cannot be trusted, because the same people wear both the scented mask and the non-scented mask, making the presence or absence of the floral
scent a confounding variable.
The results of this study can be trusted, because the presence of a floral scent reduced the time it took to complete the maze.
The results of this study cannot be trusted, because there is no control group in which participants do not wear a mask at all.
