31 Robots trained to behave like ants. Robotics researchers investigated whether robots could be trained to behave like ants in an ant colony ( Nature , Aug. 2000). Robots were trained and randomly assigned to “colonies” (i.e., groups)

consisting of 3, 6, 9, or 12 robots. The robots were assigned the tasks of foraging for “food” and recruiting another robot when they identified a resource-rich area. One goal of the experiment was to compare the mean energy expended (per robot) of the four different sizes of colonies.

a. What type of experimental design was employed?

b. Identify the treatments and the dependent variable.

c. Set up the null and alternative hypotheses of the test.

d. The following ANOVA results were reported:

F = 7.70, numerator df = 3, denominator df = 56, p@value 6 .001. Conduct the test at a significance level of a = .05 and interpret the result.