In the United States in 1969, 80% of children were involved in daily physical education programs. What was the percentage in 2005?

One day, Professor Burns came into class and put his briefcase onto the desk in the front of the room. The desk promptly fell apart and the briefcase tumbled to the floor. Because of perceptual salience, what will students be most likely to think?

a. Professor Burns ruined that desk. b. Professor Burns must not have noticed that "Caution" sign. c. Professor Burns is having an unlucky day. d. Someone must have upset Professor Burns before class.

The purpose of an adaptation period in systematic naturalistic observations is to

a. increase interobserver reliability. b. decrease training time. c. increase observer accuracy. d. decrease reactivity.