The widespread use of the scale and its impact on the field can be attributed to many factors, including its focus on strengths rather than deficits, the concept of "best performance", its capacity to capture the infant’s individuality and the overall comprehensive nature of the scale. But, perhaps, the key to its success has been the importance we placed on training and on the role trainers have played in preparing trainees to use the scale reliably in their research. Since the beginning, Dr. Brazelton has insisted that all who use the scale be trained to reliability. This has been a difficult standard to maintain, but researchers now recognize that this is essential if we hope to produce results that are reliable and research that is trustworthy. In 1985, we began to establish training sites in different sites across the world and we established a trainer network to ensure that the trainers themselves could maintain their own reliability as examiners and trainers and collaborate with each other in their research.

The widespread use of the scale and its impact on the field can be attributed to many factors, including its focus on strengths rather than deficits, the concept of "best performance", its capacity to capture the infant's individuality and the overall comprehensive nature of the scale. But, perhaps, the key to its success has been the importance we placed on training and on the role trainers have played in preparing trainees to use the scale reliably in their research. Since the beginning, Dr. Brazelton has insisted that all who use the scale be trained to reliability. This has been a difficult standard to maintain, but researchers now recognize that this is essential if we hope to produce results that are reliable and research that is trustworthy. In 1985, we began to establish training sites in different sites across the world and we established a trainer network to ensure that the trainers themselves could maintain their own reliability as examiners and trainers and collaborate with each other in their research.

This past October, NBAS trainers from Brazil, Denmark, France, Italy, Japan, Korea, Portugal, Spain, Sweden, Switzerland, Thailand, United Kingdom and the United States assembled at the Brazelton Institute to discuss their work with the NBAS and their training models, to re-check their own reliability on the NBAS and examine future directions in the NBAS and in NBAS training. There was a consensus among all these scholars that because the NBAS is a unique instrument and requires a high level of expertise to use it appropriately, it is even more important than ever to maintain high standards of examiner training, to ensure that all who use the scale learn use it appropriately and understand the principles on which it is based.

In this special issue of Ab Initio, we present a series of interviews with many of the trainers, in which they describe their experiences with the NBAS and how it has influenced their research and practice. These interviews demonstrate the impact the NBAS has had on pediatric practices across the globe and how it has "humanized" the infant for the practitioners themselves and for the parents and families with whom they work.