The amount of light entering the eye is controlled by the _____

Which of the following is NOT a drawback of longitudinal studies?

a) researchers always have a biased sample b) they are time consuming c) they are expensive d) participants may drop out over time

All of the following statements about television and very young children are accurate except

a. children who watch more hours of entertainment television tend to spend less time reading than children who watch more educational/informative programs b. children often watch television while engaging in other activities c. children who watch television programs with prosocial themes tend to have better academic outcomes in adolescence d. most studies of television's effects have used random assignment rather than quasi-experimental designs