A sample of forty couples with an irritable infant will be recruited convenientlywhen the infant is aged 7 days to 12 weeks and twenty couples assigned randomly to each group.
Úrtakið verður hentugleikaúrtak með 40 pörum foreldra óværs ungbarnsá aldrinum 7 daga -12 vikna og verða tuttugu pör valin af handahófi í hvern hóp.