In this article researchers used interviews, observations, and scales to gather information. Researchers measured stimulation in the home with the HOME inventory and collected data on 5 separate visits to their homes. The cognitive development of the infants was evaluated using the Bayley scales of infant development. Researchers also gathered data retrospectively from mothers. They had a semi-structured interview and asked the mothers if they had been breastfed and if so how long. There were also aspects of the home that were assessed such as emotional and verbal responses from the mother, punishment provision of fitting play materials.
