The purpose of this program of research was to improve teamwork during neonatal resuscitation. As in other areas of healthcare, Crisis Resource Management (CRM)-the aviation-derived teamwork model-has been incorporated into neonatal resuscitation training programs. Although there is evidence that CRM training improves teamwork during neonatal resuscitation, there are weak and inconsistent correlations between the CRM principles and teamwork behaviour. In this thesis, I argue that teamwork interventions need to be developed in context of the broader work system, and I also argue that interventions in the form of functional or cognitive aids should incorporate the science of design. Employing a user-centred design approach, I developed an intervention that is specific to the requirements of neonatal resuscitation teams-which comprises a 4-part cognitive system aid (the NeoReady TM ).In the first phase of this program of research, I reviewed the effectiveness of neonatal resuscitation teamwork training interventions to date. An analysis of the differences between aviation crews and neonatal resuscitation teams provided insight into why CRM needs to be adapted to fit the needs of the team and their environment. One example of where CRM has been adapted to suit the requirements of the domain can be seen in anaesthesia. The CRM model used in anaesthesia and other domains advocates the use of cognitive aids. I investigated the evidence supporting the use of cognitive aids, and examined how they are used in neonatal resuscitation. Although there is evidence that cognitive aids can support individuals and teams, poor design of cognitive aids can lead to unintended and adverse consequences. Moreover, cognitive aids often only support individual cognition, whereas they can be used to support the broader cognitive system, including the environment. The first phase of research concluded with an evaluation of the neonatal resuscitation decision algorithm according to human factors design principles.In the second phase of this program of research, I conducted a team task analysis based on the main steps of resuscitation as outlined in the neonatal resuscitation algorithm. The task analysis revealed some of the areas that are most vulnerable to breakdown in team coordination. I presented general classes of potential solutions. Using an existing database of video recordings of neonatal resuscitations, I illustrated that team coordination can affect patient outcomes-specifically that the transition between ceasing ventilation and commencing intubation could be improved by better team coordination.Another key contribution of this study was that it provided compelling evidence that the iii measure for intubation expertise should not be psychomotor performance, but rather how the intubation attempt affects the patient. These findings provide tangible evidence for the need to improve team coordination so to improve patient outcomes.In the third and final phase of this program of research, I describe the process of developing ...