Using a table of random numbers, the sample of 50 subjects was selected from a list of all patients giving birth in the county during the first 6 months of the year.

The sample was selected from residents of eight nursing homes in Arkansas and consisted of cognitively impaired people with no physical impairments or other psychiatric illness.

The sample selected was parents who were chosen because of their knowledge and experience of having been a parent of a child in a NICU. Inclusion criteria included those parents with a child admitted to the NICU for more than a week, gestation at birth 26 weeks or above, on a ventilator for at least 3 days, and discharged home within the last 6 months.

The sample consisted of adolescent mothers, meeting eligibility requirements, who were recruited from referrals to the Community Health Services Division of the County Health Department until the sample reached a target number of 144 participants. The patients were randomly assigned using a computer-based program into one of two groups.

To study the educational opportunities for nurses in various ethnic groups, a list of all nurses in the state of California was sorted by ethnicity. The sample consisted of 10% of the nurses in each ethnic group, selected according to a table of random numbers.

A total of 155 infants were enrolled and divided into an intervention group of 72 infants and a control group of 83 infants. A computer program that generated random numbers made assignment to intervention or control group.