Collecting follow-up data each year on the same children while they grow is the hallmark of the ____ research design

Asthma is thought to be more common among low-income, inner-city children than among suburban or rural children because of all of the following factors except ________

a. mothers may be more likely to smoke during pregnancy b. children spend more time indoors, exposed to allergens c. greater genetic susceptibility to asthma d. there are more allergens, such as cockroaches and dust mites, in inner-city homes

If an operational definition of a dependent variable is reliable, it _____

a. manipulates what it claims to manipulate b. measures what it claims to measure c. gives the same manipulation every time d. gives the same measurement every time