A student hypothesizes that high school students consuming different flavors of a drink before a spelling test will perform differently. A study to test the hypothesis finds that with a bitter drink, performance is best 6 hours after drinking it, whereas with a sweet drink, performance is better 1 hour after drinking it. An interaction between the variables complicates the researcher's explanation of the findings. Which of the following are most likely involved in this interaction?a. test scores and high school students. b. test scores and time of consumption.
c. flavor of drink and time of consumption.
d. flavor of drink and high school students.
e. flavor of drink and test scores.

Dr. laguardia is a cognitive neuroscientist who is interested in the effect of brain concussions on the ability to recognize faces. he conducts a quasi-experimental study in which he examines football players before and after the regular season using the benton facial recognition test (a published, widely used measure of one's ability to recognize faces) to compare those who received concussions to those who did not. he finds that players who had concussions during the regular season performed worse on the benton facial recognition test than did players who did not experience which of the following is true regarding external validity in dr.laguardia's study? a. because dr. laguardia selected participants who actually experienced concussions, the study b. because dr. laguardia's study is a quasi-experiment, it is impossible to obtain c. because dr. laguardia's dependent variable was assessed in the laboratory, the study d. because dr. laguardia selected a widely used measure, his study generalizes to has strong external validity. external validity has limited external validity. other applications of this measure.