Intensive, naturalistic observation studies of 3-year-olds (Tudge et al., 2006) in four different cultures showed the most common activity to be

During the second half of the first year, infants

A) recognize familiar words in spoken passages. B) start to distinguish novel sounds in human language. C) begin to display a sense of musical phrasing. D) begin to prefer listening to human speech over nonspeech sounds.

In experimental research, when the same participants are subjected to all levels of the independent variable, the design is based on a

a. repeated-measures design. b. within-subjects design. c. both a and b d. neither a nor b