Mustafa was bitten by a dog when he was five years old. Now he is afraid of any dog he sees. His fear of dog is a(n)

a. unconditioned stimulus.
b. unconditioned response.
c. conditioned stimulus

Group tests of intelligence are more economical than individual tests, in addition to being less

reliable and valid. Indicate whether the statement is true or false

Traffic signs are good examples of

a. well designed interfaces understood universally. b. interfaces that use readily understood symbols. c. interfaces that may be understood differently by different groups. d. user interfaces that are understood equally well by younger and older adults.