Gerbils were used to assess the effect of Natural Neutral, a drug designed to reduce emotionality in high-drive people. Each of 20 gerbils spent 10 solitary minutes in an open field. The investigator recorded the number of fecal boluses for each animal. Then each animal was given an injection of Natural Neutral and the open field task was repeated. No Drug Drug
mean number of boluse 6 8
standard deviation of boluses 2 2
The design of this study is:
a. paired samples;
b. independent samples;
c. testing the significance of a correlation;
d. none of the other alternatives are correct.