A pattern of excessive sleepiness during the day that continues for a period of a month or longer is called ______.

Both of Sharif's parents wear glasses to correct nearsighted vision and they're wondering whether Sharif needs glasses. Sharif's parents are concerned about Sharif's

a. depth perception. c. retinal disparity. b. visual acuity. d. cones.

Which of the following is a concern, which must be carefully considered when

interpreting the results of a field study? A) intrusion of the researcher B) presence of research participants C) the total lack of control D) the normal behaviors of the participants