Under the umbrella of ubiquitous technologies, many computational artifacts have been designed to enhance the learning experience in physical settings such as classrooms or playgrounds, but few of them focus on aiding orchestration. This paper presents a systematic evaluation of the signal orchestration system (SOS) used by students for a jigsaw activity in an authentic classroom setting. The SOS comprises multiple wearable personal signal devices and an orchestration signal manager. Color and sound signals can be configured in the manager to be transmitted to the personal devices worn by the students to indicate orchestration signals for collaboration. The comparison between the SOS and a paper-based method traditionally employed for the orchestration of the jigsaw collaborative pattern showed that students in the SOS group spent significantly less time organizing the activity, obtained higher scores in the tests, experienced a stronger feeling of group formation awareness, and reported having enjoyed the experience to a greater degree.