Caterpillar has been experimenting with replacing the traditional steering mechanism on its graders with a joystick- based steering mechanism. As a part of its research, it built graders that included both a steering wheel and joystick steering mechanisms, then asked operators to use the machines for a few days. After two days of testing, several of the operators liked the joysticks so much that they suggested the steering wheel be removed to provide better visibility. This would be an example of using an experiment to gather ___ data.
a. primary
b. secondary
c. dichotomous
d. ethnographic
e. collaborative
ANSWER: a